Fast, large-scale control of neutral atom quantum processors

Abstract

Systems and methods for performing quantum operations using a three-dimensional atomic qubit architecture are provided herein. The architecture includes an array of optical traps to store atomic qubits, the array including one or more of a launch layer, a distillation layer, a computation layer, and / or a readout layer. The architecture further includes a first mobile optical trap configured to move an ancilla qubit from the launch layer through the array along a first path, the first path passing within a blockade radius of a sequence of data qubits. An entangling laser is configured to cause the application of one or more entangling gates between the moving ancilla qubit and the data qubits.

Description

Attorney Docket No.: H0776.70195WO00FAST, LARGE-SCALE CONTROL OF NEUTRAL ATOM QUANTUM PROCESSORSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 63 / 705,483, filed October 9, 2024, and titled “FAST, LARGE-SCALE CONTROL OF NEUTRAL ATOM QUANTUM PROCESSORS,” which is incorporated herein by reference in its entirety.FEDERALLY SPONSORED RESEARCH

[0002] This invention was made with government support under W911NF-20-1-0021 and W911NF-23-2-0219 awarded by U.S. Army Research Office (ARO). The government has certain rights in the invention.BACKGROUND

[0003] Quantum information processing techniques perform computation by manipulating one or more quantum objects (e.g., objects that can store quantum states and / or manipulate quantum states). These techniques are sometimes referred to as “quantum computing.”SUMMARY

[0004] In some embodiments, the techniques described herein relate to a quantum computer, including: an array of optical traps configured to store atomic qubits in respective optical traps of the array, the array including: a vertical launch layer configured to store a first plurality of ancilla qubits; a distillation layer configured to store a first plurality of data qubits; a computation layer configured to store a second plurality of data qubits; a first mobile optical trap configured to move one ancilla qubit of the first plurality from the vertical launch layer through the array along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and second plurality; and a readout layer configured to receive the one ancilla qubit after the one ancilla qubit is moved through the distillation layer and the computation layer; at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the first plurality and ones of the sequence of data qubits of the first and second plurality - 1 - #14460931v5Attorney Docket No.: H0776.70195WO00while the first mobile optical trap moves the one ancilla qubit of the first plurality along the first path and when the one ancilla qubit of the first plurality is within the blockade radius of a data qubit of the sequence of data qubits; a camera configured to capture an image of the one ancilla qubit of the first plurality during entanglement; and at least one readout laser configured to illuminate the one ancilla qubit of the first plurality subsequent to the one ancilla qubit being loaded into the readout layer.

[0005] In some embodiments, the techniques described herein relate to a quantum computer, wherein the array of optical traps further includes a horizontal launch layer configured to store a second plurality of ancilla qubits.

[0006] In some embodiments, the techniques described herein relate to a quantum computer, wherein the array of optical traps further includes a second mobile optical trap configured to move one ancilla qubit of the second plurality from the vertical launch layer along a second path, the second path passing within a blockade radius of each of a sequence of data qubits of the second plurality.

[0007] In some embodiments, the techniques described herein relate to a quantum computer, wherein the at least one entangling laser is configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the second plurality and ones of the sequence of data qubits of the second plurality while the second mobile optical trap moves the one ancilla qubit of the second plurality along the second path and when the one ancilla qubit of the second plurality is within the blockade radius of a data qubit of the sequence of data qubits.

[0008] In some embodiments, the techniques described herein relate to a quantum computer, wherein the arrays of optical traps include optical tweezer spots generated by Talbot re-interference.

[0009] In some embodiments, the techniques described herein relate to a quantum computer, wherein the ancilla qubits of the first and second plurality are accelerated by an ancilla acceleration system, the ancilla acceleration system including: a first spatial light modulator configured to generate 2D lattice arrays using a first laser; a first acousto-optical modulator configured control the 2D lattice arrays generated by the first laser; a first acousto-optical deflector configured to control the horizontal launch layer in the array using a second laser; and a first polarizing beam splitter configured to combine laser beams generated by the first and second laser.- 2 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0010] In some embodiments, the techniques described herein relate to a quantum computer, wherein the first and / or second lasers are near-resonant lasers.

[0011] In some embodiments, the techniques described herein relate to a quantum computer, wherein the first and / or second lasers are 10-100 GHz detuned.

[0012] In some embodiments, the techniques described herein relate to a quantum computer, wherein qubit control is performed by a system of control lasers, the system including: a second acousto-optical deflector configured to direct a Raman single-qubit control beam; a third acousto-optical deflector configured to direct an entangling beam generated by the at least one entangling laser; a fourth acousto-optical deflector configured to direct a readout beam generated by the at least one readout laser; a second polarized beam splitter configured to combine the Raman single-qubit control beam and the readout beam; and a first dichroic mirror configured to filter the Raman single-qubit control beam, the readout beam, and the entangling beam.

[0013] In some embodiments, the techniques described herein relate to a quantum computer, wherein the entangling beam is a Rydberg two-qubit entangling beam.

[0014] In some embodiments, the techniques described herein relate to a quantum computer, wherein the Raman single-qubit control beam uses an amplitude modulated laser controlled by microwaves.

[0015] In some embodiments, the techniques described herein relate to a quantum computer, wherein the Rydberg two-qubit entangling beam uses a high-power laser stabilized to an ultra-low thermal expansion cavity.

[0016] In some embodiments, the techniques described herein relate to a quantum computer, wherein the readout beam uses a laser locked to an atomic resonance of the atomic qubits of the plurality of atomic qubits.

[0017] In some embodiments, the techniques described herein relate to a quantum computer, wherein the system of control lasers further includes a plurality of acousto-optical modulators to execute timing control of the plurality of lasers.

[0018] In some embodiments, the techniques described herein relate to a quantum computer, wherein the second acousto-optical deflector is configured to move the one ancilla qubit of the first plurality across the distillation layer and the computation layer.

[0019] In some embodiments, the techniques described herein relate to a quantum computer, wherein the array of optical traps are controlled by an array trapping system, the- 3 - #14460931v5Attorney Docket No.: H0776.70195WO00system including: a fifth and sixth acousto-optical deflector configured to control plane-by-plane loading and / or filling, wherein: the fifth acousto-optical deflector controls a third laser beam; and the sixth acousto-optical deflector controls a fourth laser beam; a third polarized beam splitter configured to combine the third and fourth laser beam; a focus tunable lens configured to focus the combined third and fourth laser beams; a second spatial light modulator configured to perform static 3D optical tweezer generation using a fifth laser; and a second dichroic mirror configured to filter the combined third, fourth, and fifth laser beam.

[0020] In some embodiments, the techniques described herein relate to a quantum computer, wherein the fifth laser beam is generated by a high-power laser operating at approximately 100W.

[0021] In some embodiments, the techniques described herein relate to a quantum computer, wherein the second spatial light modulator is configured to store the pluralities of data and ancilla qubits in shallow optical tweezer arrays.

[0022] In some embodiments, the techniques described herein relate to a quantum computer, wherein the second spatial light modulator is configured to generate static 3D optical tweezers using Talbot re-interference.

[0023] In some embodiments, the techniques described herein relate to a quantum computer, wherein the shallow optical tweezer arrays have a potential of less than or equal to 1 microwatt per optical tweezer.

[0024] In some embodiments, the techniques described herein relate to a quantum computer, wherein components of the quantum computer are controlled by a system of control electronics, the system including: acousto-optical modulator drivers; a global microwave oscillator (LO) configured to generate low noise oscillations; an in-phase and quadrature (IQ) controller configured to control signals produced by the LO; and a master field-programmable gate array (FPGA) configured to control operations in the system of control electronics.

[0025] In some embodiments, the techniques described herein relate to a quantum computer, wherein the master FPGA is further configured to transmit ten pairs of X / Y acousto-optical deflector signals to control a plurality of acousto-optical deflectors of the quantum computer.- 4 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0026] In some embodiments, the techniques described herein relate to a quantum computer, wherein the master FPGA is further configured to transmit between 20 and 30 transistor-transistor logic signals to the acousto-optical modulator drivers.

[0027] In some embodiments, the techniques described herein relate to a quantum computer, wherein the acousto-optical drivers are configured to execute precise acousto-optical timing control in response to the transistor- transistor logic signals.

[0028] In some embodiments, the techniques described herein relate to a quantum computer, wherein the master FPGA is further configured to transmit two 200MHz signals to the IQ controller.

[0029] In some embodiments, the techniques described herein relate to a quantum computer, wherein the IQ controller is configured to execute Ramin qubit control in response to the two 200MHz signals.

[0030] In some embodiments, the techniques described herein relate to a quantum computer, wherein the distillation layer includes a plurality of sublayers.

[0031] In some embodiments, the techniques described herein relate to a quantum computer, wherein a deep optical tweezer array is configured to move the one ancilla qubit of the first plurality sequentially through the plurality of sublayers.

[0032] In some embodiments, the techniques described herein relate to a quantum computer, wherein the first mobile optical trap is configured to move the one ancilla qubit of the first plurality at a constant speed along the first path.

[0033] In some embodiments, the techniques described herein relate to a quantum computer, wherein the second mobile optical trap is configured to move the one ancilla qubit of the second plurality at a constant speed along the second path.

[0034] In some embodiments, the techniques described herein relate to a quantum computer, wherein the constant speed is between lOm / s and lOOm / s.

[0035] In some embodiments, the techniques described herein relate to a quantum computer, wherein the ancilla and / or data qubits include alkali metals.

[0036] In some embodiments, the techniques described herein relate to a quantum computer, wherein the ancilla and / or data qubits include atoms that are alkaline-earth metals.

[0037] In some embodiments, the techniques described herein relate to a quantum computer, wherein the ancilla and / or data qubits include atoms that are alkali- and / or alkaline-earth metals.- 5 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0038] In some embodiments, the techniques described herein relate to a method for performing quantum information processing operation using an ancilla bus in a quantum computer, the method including: generating a first mobile optical trap; loading, from a vertical launch layer into the first mobile optical trap, one ancilla qubit of a first plurality; moving, by the first mobile optical trap, the one ancilla qubit of the first plurality through an array of optical traps configured to store a first and second plurality of data qubits in a respective optical trap of the array, along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and / or second plurality; at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the first plurality and ones of the sequence of data qubits of the first and second plurality while the first mobile optical trap moves the one ancilla qubit of the first plurality along the first path and when the one ancilla qubit of the first plurality is within the blockade radius of a data qubit of the sequence of data qubits; capturing an image of the one ancilla qubit of the first plurality during illumination; transferring the one ancilla qubit of the first plurality from the first mobile optical trap into a readout layer; and illuminating the readout layer with a readout laser.

[0039] In some embodiments, the techniques described herein relate to a method, wherein optical tweezer spots including the array of optical traps are generated by Talbot reinterference.

[0040] In some embodiments, the techniques described herein relate to a method, wherein moving the first plurality of ancilla qubits through the array includes: moving, by the first mobile optical trap, the first plurality of ancilla qubits through a distillation layer; and moving, by the first mobile optical trap, the ancilla qubits through a computation layer, the computation layer loaded with data qubits of a second plurality.

[0041] In some embodiments, the techniques described herein relate to a method, wherein the distillation layer includes a plurality of sublayers.

[0042] In some embodiments, the techniques described herein relate to a method, wherein the method further includes: generating a second mobile optical trap; loading, from a horizontal launch layer, a one ancilla qubit of the second plurality into the second mobile optical trap; moving, by the second optical trap, the one ancilla qubit of the second along a second path, the second path passing within a blockade radius of each of a sequence of data qubits of the second plurality stored in the computational layer; entangling the second- 6 - #14460931v5Attorney Docket No.: H0776.70195WO00plurality of data qubits and the one ancilla qubit of the second plurality; at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the second plurality and ones of the sequence of data qubits of the second plurality while the second mobile optical trap moves the one ancilla qubit of the second plurality along the second path and when the one ancilla qubit of the second plurality is within the blockade radius of a data qubit of the sequence of data qubits; capturing an image of the one ancilla qubit of the second plurality during illumination; transferring, from the computational layer, the one ancilla qubit of the second plurality into the second mobile optical trap; and transferring, from the second mobile optical trap, the one ancilla qubit of the second plurality into the horizontal launch layer.

[0043] In some embodiments, the techniques described herein relate to a method, wherein storing the pluralities of ancilla and data qubits includes storing the pluralities of ancilla and data qubits in shallow optical tweezer arrays.

[0044] In some embodiments, the techniques described herein relate to a method, wherein moving, imaging, and / or storing the one ancilla qubit of the first and second plurality includes using deep optical tweezer arrays.

[0045] In some embodiments, the techniques described herein relate to a method, wherein measuring the one ancilla qubit of the first and / or second plurality includes determining a state of the one ancilla qubit of the first and / or second plurality.

[0046] In some embodiments, the techniques described herein relate to a method, wherein the method further includes replacing lost qubits in any of the vertical launch layer, the distillation layer, the computational layers, the horizontal launch layer, and the readout layer by transferring atoms stored in a bulk array in the quantum computer.

[0047] In some embodiments, the techniques described herein relate to a method, wherein atoms stored in the array are continuously supplied via a lattice conveyer belt configured to transport cold atoms into the quantum computer.

[0048] In some embodiments, the techniques described herein relate to a method, wherein entangling the one ancilla qubit of the first plurality and the data qubits of the first plurality includes performing a transversal entangling gate.

[0049] In some embodiments, the techniques described herein relate to a method, wherein the plurality of qubits may be entangled to create a Greenberger-Home-Zellinger (GHZ) state.- 7 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0050] In some embodiments, the techniques described herein relate to a method, wherein the method is configured to distill magic states.

[0051] In some embodiments, the techniques described herein relate to an atomic clock, including: an array of optical traps configured to store pluralities of atomic qubits in respective optical traps of the array, the pluralities of atomic qubits including: a first plurality of ancilla qubits; a first plurality of data qubits; and a second plurality of data qubits; at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the first plurality and ones of the sequence of data qubits of the first and second plurality while the first mobile optical trap moves the one ancilla qubit of the first plurality along the first path and when the one ancilla qubit of the first plurality is within the blockade radius of a data qubit of the sequence of data qubits; at least one laser configured to illuminate the one ancilla qubit of the first plurality subsequent to applying the sequence of entangling gates; and a camera configured to capture an image of the one ancilla qubit of the first plurality during illumination.

[0052] In some embodiments, the techniques described herein relate to an atomic clock, wherein the array includes: a vertical launch layer configured to store the first plurality of ancilla qubits; a distillation layer configured to store the first plurality of data qubits; a computation layer configured to store the second plurality of data qubits; a first mobile optical trap configured to move one ancilla qubit of the first plurality from the vertical launch layer through the array along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and second plurality; and a readout layer configured to receive the one ancilla qubit after the one ancilla qubit is moved through the distillation layer and the computation layer.

[0053] In some embodiments, the techniques described herein relate to an atomic clock, wherein the array of optical traps further includes a horizontal launch layer configured to store a second plurality of ancilla qubits.

[0054] In some embodiments, the techniques described herein relate to an atomic clock, wherein the array of optical traps further includes a second mobile optical trap configured to move one ancilla qubit of the second plurality from the vertical launch layer along a second path, the second path passing within a blockade radius of each of a sequence of data qubits of the second plurality.- 8 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0055] In some embodiments, the techniques described herein relate to an atomic clock, wherein the at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the second plurality and ones of the sequence of data qubits of the second plurality while the second mobile optical trap moves the one ancilla qubit of the second plurality along the second path and when the one ancilla qubit of the second plurality is within the blockade radius of a data qubit of the sequence of data qubits.

[0056] In some embodiments, the techniques described herein relate to an atomic clock, wherein the arrays of optical traps include optical tweezer spots generated by Talbot reinterference.

[0057] In some embodiments, the techniques described herein relate to an atomic clock, wherein an atomic time unit is quantified by a wavelength of light emitted by any one of the first pluralities of data qubits during a deexcitation event.BRIEF DESCRIPTION OF DRAWINGS

[0058] FIG. 1 is a schematic diagram of an illustrative architecture for fast, large scale computation, according to some embodiments of the technology described herein.

[0059] FIGs. 2A-2B are schematic diagrams of relative optical tweezer depth, according to some embodiments of the technology described herein.

[0060] FIG. 3 is a flowchart illustrating an iterative assembly technique, according to some embodiments of the technology described herein.

[0061] FIGs. 4A-4E show time steps of ancilla rastering in a distillation layer of the architecture of FIG. 1, according to some embodiments of the technology described herein.

[0062] FIGs. 5A-5B are schematic views of acceleration methods applied to an ancilla qubit, according to some embodiments of the technology described herein.

[0063] FIG. 6 is a graph of the velocity of an ancilla qubit of FIGs. 4A-4E over time with a corresponding schematic of applied quantum gates, according to some embodiments of the technology described herein.

[0064] FIG. 7 is a flowchart depicting a method of quantum information processing operation using an ancilla bus in a quantum computer, according to some embodiments of the technology described herein.- 9 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0065] FIG. 8 is an illustrative architecture suitable for fast stability measurement, according to some embodiments of the technology described herein.

[0066] FIG. 9 is an illustrative architecture suitable for fast routing, according to some embodiments of the technology described herein.

[0067] FIG. 10 is an illustrative architecture for cavity array readout, according to some embodiments of the technology described herein.

[0068] FIG. 11 is an illustrative architecture for heralded long-range entanglement, according to some embodiments of the technology described herein.

[0069] FIGs. 12A-12D show illustrative steps of parallel Greenberger-Horne-Zeilinger (GHZ) state creation, according to some embodiments of the technology described herein.

[0070] FIG. 13 illustrates a method for local addressing, according to some embodiments of the technology described herein.

[0071] FIG. 14 illustrates a magic state distillation circuit, according to some embodiments of the technology described herein.

[0072] FIG. 15 illustrates stabilizer measurements on low-density parity-check (LDPC) codes, according to some embodiments of the technology described herein.

[0073] FIG. 16 illustrates iterative sensing for an illustrative atomic clock, according to some embodiments of the technology described herein.

[0074] FIG. 17 is a schematic view of an optical train for generation of a three-dimensional (3D) optical tweezer array, according to some embodiments of the technology described herein.

[0075] FIG. 18 is an illustrative Talbot re-interference pattern generated by the optical train of FIG. 17, according to some embodiments of the technology described herein.

[0076] FIG. 19 is schematic diagram of an apparatus for quantum processing, according to some embodiments of the technology described herein.

[0077] FIG. 20 is a schematic diagram of the ancilla acceleration component 2000 of the apparatus 1900 of FIG.19, according to some embodiments of the technology described herein.

[0078] FIG. 21 is a schematic diagram of the control lasers 2100 of the apparatus 1900 of FIG. 19, according to some embodiments of the technology described herein.- 10 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0079] FIG. 22 is a schematic diagram of the array trapping and iterative assembly components 2200 of the apparatus 1900 of FIG. 19, according to some embodiments of the technology described herein.

[0080] FIG. 23 is a schematic diagram of the control electronics 2300 of the apparatus 1900 of FIG. 19, according to some embodiments of the technology described herein.

[0081] FIG. 24 is a level diagram showing87Rb atomic levels, according to some embodiments of the technology described herein.DETAILED DESCRIPTION

[0082] The present disclosure provides techniques and apparatus for implementing large, scalable quantum architectures by leveraging three-dimensional (3D) optical lattice architectures and accelerating atomic qubits during operation.

[0083] In classical computers, bits are a unit of information representing a logical state of one of two classical values, 0 or 1. Similarly, a quantum bit (a “qubit” herein) is a unit of information in a quantum computer. Like classical bits, qubits can occupy two distinct states, such as |0) and |1), or any quantum superposition of the two states. In some cases, qubits are encoded in quantum systems with two or more distinct quantum states. Many physical realizations of qubits may be employed. As an example, qubits may include neutral atoms isolated within a vacuum chamber. These isolated neutral atoms have many distinct quantum states corresponding to the orientation of electron spins, electron orbits, nuclear spins, molecular rotations, and / or the like.

[0084] Quantum computers generally contain many qubits (e.g., tens, hundreds, and / or thousands of qubits) and perform computational operations, including initializing the qubits for computation, manipulating the state and / or position of the qubits, and reading out the state of the qubits at a given time. Manipulation of the qubit state may be performed using quantum logic gates, which perform mathematical operations on qubits. Two such types of quantum logic gates include a single-qubit gate and / or a multi-qubit gate. A single-qubit gate is a quantum logic gate applied to an individual qubit. For example, a single qubit gate may operate on a qubit in state |0) and change (e.g., flip) the qubit state to state |1). In contrast, a multi-qubit gate operates on at least two qubits. A multi-qubit gate may, as an example, entangle two or more qubits, wherein entangling describes linking the quantum states of the two or more qubits such that the state of one influences the state of another.- 11 - #14460931v5Attorney Docket No.: H0776.70195WO00One common multi-qubit gate is a controlled NOT gate (“CNOT gate”), which can entangle two qubits and conditionally change the state of one or both qubits. For example, a CNOT gate may be configured to flip the state of a second qubit if and only if the state of a first qubit is |0).

[0085] According to various embodiments of a quantum computer, individual particles (e.g., atoms, ions, molecules, etc.) can first be trapped in an array and arranged into particular configurations. Next, one or more of the arranged particles are prepared in a desired quantum state to act as a qubit. Quantum circuits may then be implemented by performing a sequence of qubit operations, which act on individual qubits (“single-qubit gates”) or on groups of two or more qubits (“multi-qubit gates”). Finally, the state of the qubits can be read out in order to observe the result of the quantum circuit. The readout can be accomplished using an observation system that typically includes an electron-multiplied CCD (EMCCD) or optical camera image to detect particles’ loaded positions, and a second camera image to read out the qubits’ final states by, for example, detecting fluorescence generated by the particles in their final quantum states.

[0086] The operation of quantum information platforms are based on interactions between qubits. However, qubits often interact locally, which limits the connectivity of the circuit or the analog simulation and constrains the possible computations. While some platforms can communicate in a non-local way through the use of a shared bus, these shared-bus approaches are limited to small systems and thus still require a way to dynamically move qubits around in order to truly scale up the platform.

[0087] In many embodiments of a quantum computer, a qubit may be encoded in two near-ground-state energy levels of an atom, ion, or molecule. An example of this is a hyperfine qubit. In a hyperfine qubit, the two near-ground-states differ by the relative orientation of the nuclear spin with respect to the outer electron spin. The two states are split by the interaction energy between the nuclear spin and electron spin, typically ranging from frequencies of 1-13 GHz. Hyperfine qubits are frequently chosen owing to their resistance to environmental perturbations and long lifetimes.

[0088] Performing single-qubit gates on hyperfine qubits can be done by applying coherent microwave radiation at the frequency of the energy splitting between the first and second hyperfine qubit states. However, due to the physical proximity of the qubits in the quantum computer, in some systems on the scale of a few microns, microwaves cannot be- 12 - #14460931v5Attorney Docket No.: H0776.70195WO00applied to the first qubit without the microwaves affecting the states of qubits proximate to the first qubit.

[0089] Alternatively, some quantum information processing systems may apply a specific type of laser field to the qubits to perform quantum logic gates. This laser field is nearly resonant with an optical transition from one of the ground states to an optically excited state of a particular qubit. By applying the laser field to the qubit (i.e. pumping into the qubit), the qubit absorbs a nearly resonant first wavelength and generates a second wavelength, and in doing so changes its state. This state change is defined as a stimulated Raman transition (SRT) and the laser field defined as a Raman pulse. Beneficially, the Raman pulse can focus on individual qubits and / or subsets of qubits, mitigating the unintended state changes faced in microwave state transitions. Additionally, Raman pulses can be applied with high intensity, resulting in faster quantum gate operations.

[0090] Neutral atom quantum computers are a specific type of quantum computer that encode qubits in neutral atoms. These neutral atoms are trapped in a vacuum chamber and levitated by one or more trapping lasers. Commonly, individual atoms are trapped in an optical lattice, which is formed from standing waves of laser light that produces a periodic structure of nodes and anti-nodes. Alternatively or additionally, optical tweezers may be used to trap individual atoms by using tightly focused laser beams.

[0091] Neutral atom qubits can be used as hyperfine qubits, wherein a first and second ground state is split by frequencies of approximately 1-13 GHz. Multi-qubit gates in neutral atom quantum computers are realized using a third state, which is an excited Rydberg state. Beneficially, when an atom is excited to a Rydberg state, proximal atoms are prevented from exciting to the Rydberg state. This conditional behavior forms the basis for multi-qubit gates, including the CNOT gate previously described. The Rydberg state is used to temporarily mediate the multi-qubit gate before Rydberg excited atoms return to ground state, preserving their coherence. Coherence is a measure of the lifetime of the qubit before its information is lost, and is a parameter frequently used to describe qubits.

[0092] Neutral atom arrays can be dynamically reconfigured while preserving quantum coherence and entanglement between qubits by storing quantum information in hyperfine states and shuttling atoms in optical tweezers. This approach offers a scalable way to realize a quantum information system with large numbers of qubits and arbitrary programmability - where any qubit can perform an entangling gate with any other qubit in the array. Using- 13 - #14460931v5Attorney Docket No.: H0776.70195WO00high-fidelity two-qubit Rydberg gates, various quantum information circuits are described herein that leverage the programmability and nonlocal connectivity achievable with these approaches. Examples of high fidelity Rydberg gates are described in Levine, et al., Parallel Implementation of High-Fidelity Multiqubit Gates with Neutral Atoms, Phys. Rev. Lett., vol. 123, issue 17, link.aps.org / doi / 10.1103 / PhysRevLett.123.170503, and Evered, et al., High-Fidelity Parallel Entangling Gates on a Neutral Atom Quantum Computer, arXiv:2304.05420 [quant-ph], arxiv.org / abs / 2304.05420, which are hereby incorporated by reference in their entirety.

[0093] In quantum computers, ideal qubits are encoded to have long coherence properties and, consequently, maintain their lifetime before information is lost. Short coherence properties result in a higher error rate and increased information loss. One common error in quantum computation is a bit-flip error, wherein a qubit’ s state changes unexpectedly. For example, a quantum qubit encoded in state |0) may change to state |1) after a characteristic time scale, wherein the characteristic time scale defines the qubit’s coherence. As another example, a qubit in a superposition state (|0) + 11)) / 2 may change to state (|0) — |1)) / V2 after a characteristic time scale. A challenge of quantum computation is that computation speeds and data handling depend on the number of atoms within the quantum computer. Three-dimensional interference of light can greatly increase the number of trapped atoms using the same amount of laser power as compared to two-dimensional configuration, and greatly expands available working space. Three-dimensional interference of optical tweezers may be provided by the Talbot effect.

[0094] In Talbot re-interference, each optical tweezer, composed of various angles of light ray, diverges after focus. These diverging rays intersect with diverging rays from other optical tweezers, and if in regular patterns, will remerge. Half-integer planes occur at — ; b A is spacing in-plane, A is wavelength (5 um spacing -> 30 um). In an N x N array, the number of principal re-interferences will be approximately N. For a 100 x 100 array, this gives 100 extra layers. For a 1000 x 1000 array this gives 1000 extra layers. Additional re-interference happens at sub-integer spacings as well. These plans have more optical tweezer spots, but leading to reduced intensity per spot. By superimposing multiple Talbot arrays at slightly different wavelength, these can be used as well. This can further increase the number of usable, well- spaced planes by a factor of approximately four.- 14 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0095] Altogether, these techniques allow creating approximately 100 planes separated by approximately 10-30 pm. These are sufficiently separated such that an individual plane can be resolved without disturbing the neighboring planes, both for Raman / Rydberg addressing from the side, as well as for placing arrays. Even without reduced optical tweezer power per trap, this leads to > IM well-separated (spaced by approximately 5-10 pm) optical tweezer sites in an approximately 1 mm x 1 mm x 1 mm region, addressable with existing commercial optics. Reducing optical tweezer depth as well can allow for approximately one million manipulated sites with dimensions of approximately 5 mm x 5 mm x 5 mm.

[0096] Employing Talbot re-interference in atomic array generation can be used to increase the number of trapped atoms by a factor of approximately 100 through repeated reinterference of optical tweezer beams out-of-plane, creating approximately 100 well-resolved planes. To further increase the number of trapped atoms, one can iteratively build and control large arrays: during execution of logic gates or sensing, atoms are stored in optical traps that are approximately 100 to 1000 times shallower than deeper optical traps that are only briefly used on subsets of atoms for loading (e.g., moving) and imaging. These techniques can result in a 105-fold increase in the number of trapped atoms relative to alternative approaches that achieve 103-104 atoms.

[0097] The inventors have recognized and appreciated that certain implementations of 3D trapping include imaging of many planes, greatly complicating control of the atomic qubits, and that shallow optical tweezers reduce movement speed of atomic qubits, thereby reducing overall computation speed. However, specific applications can potentially dramatically change control requirements. To this end, embodiments of the present disclosure interface with the intrinsic parallelism of QEC and metrology and combine with architectures that enable new processing modalities.

[0098] In some embodiments, an atomic launch pad and fast read / write architecture is provided. Atomic qubits can be reconfigured during a computation, leading to significant overhead reductions in QEC and direct realization of metrological states, but limiting processing speed. Importantly, motion speed is not limited by velocity, but rather by starting and stopping. For this reason, various embodiments employ pre-acceleration of ancilla atoms from an “atomic launch pad,” using optical tweezers or optical lattice potentials to reach velocities of 10-100 m / s, and then realize all processing only at constant velocity. In this approach, the ancillas are put in superposition while already at high velocity, realize- 15 - #14460931v5Attorney Docket No.: H0776.70195WO00precisely timed Rydberg gates with the stationary data atoms, and are then rotated into the computational basis and measured. This allows motion speed-ups by a factor of approximately 100, eliminates key technical bottlenecks such as transferring qubits between potentials, and enables storing the data qubits in extremely shallow potentials (above). As these accelerating potentials do not need to preserve qubit coherence, they can be near-resonant to the atomic transition, enabling strong forces with minimal power.

[0099] The inventors have further recognized and appreciated that as the atomic launch pad provides speed-ups, novel control approaches may be employed, as space, time, and control are all inter-related. For example, greater speed allows serializing, lending to simplified control and increased space. While simultaneous imaging of 3D planes is challenging, the fast-moving atoms can be used to measure qubits inside the array, allowing optical readout at a single plane. Moreover, whereas programming certain circuits can be complex, having qubits streaming across the array enables circuit programming exclusively realized by pulse timings, controlling whether stationary qubits are entangled via the flying ancilla “bus.” Such fast-moving ancillas can also be used for heralded Bell pair generation between modules, and for interfacing with optical cavities placed millimeters away to avoid affecting Rydberg gates.

[0100] In some embodiments, the techniques include dynamic zone architecture and lattice addressing. Serializing to increase qubit numbers and simplifying calibrations costs time and is very wasteful with available laser power. For example, such approaches involve atom reconfiguration for hundreds of microseconds, and then a global entangling gate is pulsed for hundreds of nanoseconds. Instead, with dynamic zones, power-limited zones such as the entangling and clock laser zones can be quickly scanned across the array, allowing continuous gate operation with the same laser power, increasing accessible atom numbers 103-fold before incurring serialization overheads, and offering unique control opportunities in 3D.

[0101] Beneficially, an advantage of this read / write approach to 3D control is that imaging can be performed only at one plane, and operations and selective readout are realized through pulse timing to entangle data qubits with the ancilla bus.

[0102] The architectures provided herein are application to various atomic species. These include Alkali, such as Rb / Cs; Alkaline-earth such as Yb / Sr; and dual species arrays with any combination of the above. Yb atoms in the data array can be stored in very shallow- 16 - #14460931v5Attorney Docket No.: H0776.70195WO00potentials and thereby have a long clock lifetime, which is otherwise limited by Raman scattering from the laser due to higher excited states. The ancilla atom can be launched in the ground state where it’ s insensitive to scattering, and the data atom are stored in the clock state where they are safe from the potentials and / or light interacting with the ancilla array.

[0103] Following below are more detailed descriptions of various concepts related to, and embodiments of, techniques for three-dimensional construction and iterative control for computation using atomic qubits. It should be appreciated that various aspects described herein may be implemented in any of numerous ways. Examples of specific implementations are provided herein for illustrative purposes only. In addition, the various aspects described in the embodiments below may be used alone or in any combinations and are not limited to the combinations explicitly described herein.

[0104] FIG. 19 shows an illustrative apparatus 1900 for quantum processing, in accordance with some embodiments of the technology described herein. The apparatus 1900 includes an atom array 1902 disposed in a vacuum chamber 1904. The atom array 1902 is fed new atoms by a 3D magnetooptical trap (MOT) 1906. The atom array 1902 may include optical trap lattices discussed herein in connection with the example of FIG. 1 (e.g., the distillation layer 104 and / or computation layer 108).

[0105] In some embodiments, the illustrative apparatus 1900 further includes an ancilla acceleration component 2000, control lasers 2100, array trapping and iterative assembly components 2200, and control electronics 2300. A CMOS camera 1908 is arranged to detect atomic fluorescence 1910 from a readout layer of the atom array 1902 (e.g., the readout layer 106, as described in connection with FIG. 1 herein). Signals from the CMOS camera 1908 are transmitted to the control electronics 2300 via a field-programmable gate array (FPGA) 1912.

[0106] In some embodiments, the array trapping and iterative assembly components 2200 are optically coupled to the atom array 1902 via a first objective lens 1914A. The ancilla acceleration components 2000 are optically coupled with the atom array 1902 via a second objective lens 1914B.

[0107] In some embodiments, the ancilla acceleration component 2000 is configured to accelerate and / or launch ancilla qubits (e.g., ancilla qubits 412 as described herein in connections with FIGs. 4A-4E) through the atom array 1902, as described below in- 17 - #14460931v5Attorney Docket No.: H0776.70195WO00connection with FIGs. 5-6. An illustrative configuration of the ancilla acceleration component 2000 is provided in FIG.20.

[0108] In some embodiments, the ancilla acceleration component 2000 includes a first spatial light modulator (SLM) 2002, a first laser 2004, a first acousto-optic modulator (AOM) 2006, a first acousto-optic deflector (AOD) 2008, a second laser 2010, and a first polarizing beam splitter (PBS) 2012. In some embodiments, the first and / or second lasers 2004, 2010 are near-resonant lasers. In some embodiments, the first and / or second lasers 2004, 2010 are detuned by 10-100 GHz.

[0109] In some embodiments, the first SLM 2002 is configured to generate one or more two-dimensional (2D) lattice arrays using the first laser 2004. The first AOM 2006 is configured to control the 2D lattice arrays generated by the first SLM 2002. The first AOD 2008 is configured to accelerate ancilla atoms during operation of the quantum computer (described herein in connection with the example of FIG. 5) using the second laser 2010. The first PBS 2012 is configured to combine laser beams generated by the first and second lasers 2004, 2010.

[0110] Returning to the embodiment of FIG. 19, the apparatus 1900 further includes control lasers 2100 configured to execute single-qubit control. An illustrative configuration of the control lasers 2100 is provided in the example of FIG.21.

[0111] FIG. 21 shows an illustrative embodiment of the control lasers 2100 of the apparatus 1900 of FIG. 19. The control lasers 2100 include a second AOD 2102, a third AOD 2104, a fourth AOD 2106, a second PBS 2108, and a first dichroic mirror 2110. The control lasers 2100 further include a second AOM 2112, a Raman single-qubit control laser 2114, a third AOM 2116, an entangling laser 2118, a fourth AOM 2120, and a readout laser 2122.

[0112] In some embodiments, the second, third, and / or fourth AOM 2112, 2116, 2120 may be configured to execute timing control of the Raman single-qubit control laser 2114, the entangling laser 2118, and the readout laser 2122, respectively.

[0113] In some embodiments, the second AOD 2102 is configured to spatially direct the Raman single-qubit control laser 2114 beam, with or without the second AOM 2112. The second AOD 2102 may be further configured to cause an optical trap, storing an ancilla qubit, to move through one or more layers of the atom array 1902 (e.g., including one or- 18 - #14460931v5Attorney Docket No.: H0776.70195WO00more of the distillation layers 104 and / or the computation layer 108) during a quantum computing operation.

[0114] In some embodiments, the third AOD 2104 is configured to direct the entangling laser 2118, with or without the third AOM 2116. In some embodiments, the Raman singlequbit control laser 2114 beam may use a high-power laser which has been stabilized to an ultra-low thermal expansion cavity. In some embodiments, the entangling laser 2118 beam may be a Rydberg two-qubit entangling beam.

[0115] In some embodiments, the third AOD 2106 is configured to direct the readout laser 2122 with or without the fourth AOM 2120. In some embodiments, the readout laser 2122 has a frequency that is locked to an atomic resonance of an atomic species forming one or more qubits that are trapped in the atom array 1902.

[0116] As shown in FIG. 21, and in some embodiments, the second PBS 2108 is configured to combine one or more laser beams from the readout laser 2122 and the Raman single-qubit control laser 2114. The combined beam(s) may then pass through the first dichroic mirror 2110 prior to entering the atom array 1902.

[0117] Returning to the example of FIG. 19, the apparatus 1900 further includes array trapping and iterative assembly components 2200, as illustrated in FIG. 22. In some embodiments, the array trapping / iterative assembly components 2200 are configured to perform lattice trapping and iterative assembly as described in connection with the examples of at least FIGs. 2-3 herein. As shown in the example of FIG. 22, the array trapping and iterative assembly components 2200 include a fifth AOD 2202, a sixth AOD 2204, a third laser 2206, a fourth laser 2208, a third PBS 2210, a focus-tunable lens 2212, a second SLM 2214, a fifth laser 2216, and a second dichroic mirror 2218.

[0118] In some embodiments, the fifth AOD 2202 is configured to spatially control the third laser 2206 beam, and the sixth AOD 2204 is configured to control the fourth laser 2208 beam. In some embodiments, the fifth and sixth AODs 2202, 2204 are configured to control plane-by-plane loading and / or filling.

[0119] In some embodiments, the third PBS 2210 is configured to combine beams output by the third and fourth lasers 2206, 2208. The focus-tunable lens 2212 is configured to focus the combined beams output from the third PBS 2210.

[0120] In some embodiments, the second SLM 2214 includes a microlens array for static 3D optical tweezer generation using a beam output by the fifth laser 2216. In some- 19 - #14460931v5Attorney Docket No.: H0776.70195WO00embodiments, the fifth laser 2216 operates at a laser power approximately equal to 100W. In some embodiments, the second SLM 2214 is configured to generate the static 3D optical tweezers using Talbot re-interference, as described herein. The static 3D optical tweezers may be used to store pluralities of data and / or ancilla qubits in shallow optical tweezer arrays to form one or more layers of the atom array 1902 (e.g., including vertical launch layer 102 and / or distillation layers 104). These shallow optical tweezer arrays have a potential of approximately 1 pW per optical tweezer or less. In some embodiments, the second dichroic mirror 2218 is configured to combine the output beam(s) from the focus-tunable lens 2212 and the second SLM 2214.

[0121] Returning to FIG. 19, in some embodiments, the apparatus 1900 includes control electronics 2300, as illustrated in FIG. 23. The control electronics 2300 are configured to perform quantum gate control, acousto-optical modulator (AOM) timing control, and / or acousto-optical deflector (AOD) control. In some embodiments, the control electronics 2300 include AOM drivers 2302, a global microwave oscillator (LO) controller 2304, an in-phase and quadrature (IQ) controller 2306, and a master FPGA 2308.

[0122] In some embodiments, the LO controller 2304 connects to the IQ controller 2306 and provides a reference frequency to the IQ controller 2306. The IQ controller 2306 is configured to execute Raman qubit control using two 200MHz signals sent by the master FPGA 2308 to the IQ controller 2306.

[0123] In some embodiments, the master FPGA 2308 may transmit between 20 and 30 transistor-transistor logic signals (TTLs) to the AOM drivers 2302. The AOM drivers 2302 are configured to execute precise acousto-optical timing control (e.g., of any of the AOMs described in connection with FIGs. 20-22) using the TTLs sent by the master FPGA 2308 to the AOM drivers 2302.

[0124] In some embodiments, the master FPGA 230 may also be configured to generate and transmit ten pairs of X / Y AOD signals to the apparatus 1900. The X / Y AOD signals may be configured to control deflections in the x- and y-directions by one or more of the AODs of apparatus 1900. These X / Y AOD signals may be received by any of the AODs described in connection with FIGs. 20-22 herein. For example, the X / Y AOD signals may be received by the fifth AOD 2202 and the sixth AOD 2204 of the array trapping and iterative assembly components 2200.- 20 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0125] FIG. 1 is an illustrative architecture 100 for fast, large scale quantum computing. The architecture 100 includes a vertical launch layer 102, distillation layers 104, and a readout layer 106. The architecture 100 may also optionally include a computation layer 108. In some embodiments, the architecture 100 has a volume of 1 cubic mm or less. As depicted in FIG. 1, the distillation layers 104 may include a plurality of sublayers 110. Though the example of FIG. 1 shows eight sublayers 110, it should be appreciated that in some embodiments, there may be fewer sublayers 110 or more sublayers 110 (e.g., on the order of one hundred sublayers 110) than are depicted in the example of FIG. 1.

[0126] In some embodiments each of vertical launch layer 102, distillation layers 104, computation later 108, and readout layer 106 are divided into a plurality of zones 114. In some embodiments, the second SLM 2214, as described in connection with FIG.22 herein, is configured to generate 3D optical tweezer arrays that make up the layers (e.g., the vertical launch layer 102, the distillation layers 104, etc.) of the architecture 100.

[0127] In some embodiments, the vertical launch layer 102 may be configured to store and launch ancilla qubits (e.g., ancilla qubits 412 as described in connection with FIGs.4A-4E herein). During performance of quantum computing operations, ancilla qubits stored in the vertical launch layer 102 are moved (e.g., using a mobile optical trap) along paths in the z-direction such that they pass through the one or more distillation layers 104 and / or the computation layer 108. In some embodiments, the first SLM 2002 is configured to generate the mobile optical trap and the first AOD 2008 is configured to control the spatial position of the mobile optical trap.

[0128] In some embodiments, the distillation layers 104 are configured to store data qubits (e.g., data qubits 414 as described in connection with FIGs. 4A-4E herein). In embodiments where the architecture 100 optionally includes a computation layer 108, the distillation layers 104 are configured to store a first plurality of data qubits, and the computation layer 108 is configured to store a second plurality of data qubits.

[0129] In some embodiments, the architecture optionally includes horizontal launch layers 112A and / or 112B. In such embodiments, the vertical launch layer 102 is configured to store a first plurality of ancilla qubits and the horizontal launch layers 112 are configured to store a second plurality of ancilla qubits. During performance of quantum computing operations, ancilla qubits stored in the first launch layer 112A are moved in the y-direction, and ancilla qubits stored in the second launch layer 112B are moved in the x-direction (e.g.,- 21 - #14460931v5Attorney Docket No.: H0776.70195WO00by mobile optical traps). That is, the second plurality of ancilla qubits launched from the horizontal launch layers 112 traverse only the computation layer 108.

[0130] In some embodiments, the readout layer 106 is configured to receive and store ancilla qubits moved from the vertical launch layer 102 and through the distillation layers 104 . In some embodiments, the readout layer 106 also receives the first plurality of ancilla qubits after the first plurality of ancilla qubits 412 pass through the computation layer 108.

[0131] FIGs. 2A-2B depicts relative optical tweezer depth for individual potential wells 200 and optical tweezer arrays 220 used in embodiments described herein. FIG. 2A depicts deep potential wells 202 and shallow potential wells 204. FIG. 2B depicts deep optical tweezer arrays 222 and shallow optical tweezer arrays 224.

[0132] In some embodiments, a plurality of deep potential wells 202 make up the deep optical tweezer arrays 222. The deep optical tweezer arrays 222 may be used to load atomic qubits into the shallow optical tweezer arrays 224. The deep optical tweezer arrays 222 may further be configured to hold atomic qubits for imaging and / or to move atomic qubits through one or more layers of the architecture 100. The first SLM 2002 described in connection with FIG. 20 herein may be configured to generate the deep optical tweezer arrays 222.

[0133] In some embodiments, a plurality of shallow potential wells 204 form the shallow optical tweezer arrays 224. The shallow optical tweezer arrays 224 are configured to store atomic qubits in the layers described in the architecture 100 of FIG. 1. The optical tweezer depth of the shallow potential wells 204 is reduced by a factor of approximately 100 to 1000 during logic and / or sensing in comparison to the optical tweezer depth of the deep potential wells 202 of deep optical tweezer arrays 222. In some embodiments, the second SLM 2214 described in connection with FIG. 20 herein may be configured to generate the shallow optical tweezer arrays 224.

[0134] FIG. 3 is a flowchart describing an iterative assembly technique 300 used to refill lost atomic qubits during operation of the quantum computer, in accordance with some embodiments of the technology described herein. The iterative assembly technique 300 may be implemented using a suitable quantum computing architecture (e.g., architecture 100) and / or quantum computing apparatus (e.g., apparatus 1900) in combination with one or more classical computing devices (e.g., FPGAs, classical circuitry, personal or rack-based- 22 - #14460931v5Attorney Docket No.: H0776.70195WO00computers, etc.) configured to control elements of the quantum computing architecture and / or apparatus.

[0135] In some embodiments, the iterative assembly technique 300 begins at block 302 in which atoms from a bulk atom supply are loaded into a conveyer belt to form a continuous atom stream. The atoms may be loaded using, for example, the fifth AOD 2202 and / or the sixth AOD 2204. The atoms may be loaded from a bulk atom supply stored in the 3D MOT 1906. Unsorted, cold atoms can be streamed in continuously via the lattice conveyor belt. The lattice conveyer belt provides a constant supply of atoms that can be then sorted and rapidly accelerated for processing in the array. This continuous stream of atoms available for resupplying lost atoms is referred to as a conveyer belt, according to some embodiments.

[0136] In some embodiments, the iterative assembly technique 300 may continue to block 304, in which atoms from the conveyer belt are loaded into a deep tweezer array. The atoms may be loaded into the deep tweezer array using, for example, the fifth AOD 2202 and sixth AOD 2204. In some embodiments, the fifth AOD 2202 and / or the sixth AOD 2204 are also configured to generate the deep optical tweezer array (e.g., by altering a depth of a potential well of the optical tweezers forming the array). In some embodiments, approximately 10,000 atoms may be loaded into the deep optical tweezer array at block 304. In other embodiments, more or fewer atoms may be loaded into the deep optical tweezer array.

[0137] In some embodiments, the iterative assembly technique 300 may continue to block 306, in which the atoms in the deep tweezer array are imaged, rearranged, and cooled. In some embodiments, the CMOS camera 1908 is configured to image the atoms by capturing fluorescence signals emitted by the atoms (e.g., in response to illumination). In some embodiments, the fifth AOD 2202 and the sixth AOD 2204 may be used to rearrange the atoms in the deep optical tweezer array. In some embodiments, the Raman single-qubit control laser 2114 is configured to cool the atoms in the deep optical tweezer array using Raman sideband cooling. When cooled by Raman sideband cooling, the atoms in the deep optical tweezer arrays may be cooled close to a motional ground state.

[0138] In some embodiments, the iterative assembly technique 300 may continue to block 308, in which the deep tweezer array may be shifted into a plane-to-fill in a shallow tweezer array. For example, the fifth AOD 2202 and / or the sixth AOD 2204 may be used to- 23 - #14460931v5Attorney Docket No.: H0776.70195WO00shift the deep optical tweezer array into a plane-to-fill (e.g., an optical tweezer array with lost atoms). This plane-to-fill may be a shallow 2D or 3D optical tweezer array.

[0139] In some embodiments, the iterative assembly technique 300 may continue to block 310, in which the deep tweezer array may be lowered into the shallow tweezer array. For example, the fifth AOD 2202 and the sixth AOD 2204 may move the deep optical tweezer array into the plane-to-fill in the shallow 2D and / or 3D shallow optical tweezer array, thereby transferring the trapped atoms from the deep optical tweezer array to the 2D and / or 3D shallow optical tweezer array.

[0140] In some embodiments, an acceptable threshold for known qubit loss is approximately 1-10%, and so qubit replenishment is configured to occur approximately every 100 Rydberg gate layers. In other embodiments, qubit replenishment may occur sooner or later than every 100 Rydberg gate layers.

[0141] FIGs. 4A-4E show a time lapse of rastering 400 (e.g., as may be performed in the architecture 100 shown in FIG. 1). In the example shown in FIGs.4A-4E, rastering 400 is a five step process, including acceleration 402, a first illuminated entanglement 404, displacement 406, a second illuminated entanglement 408, and deceleration 410, though it should be appreciated that fewer or additional entanglement steps may be performed as part of rastering 400, in some embodiments. Rastering 400 describes a process of performing quantum operations between an ancilla qubit originating from the vertical launch layer 102 or the horizontal launch layers 112A and / or 112B and data qubits stored in the plurality of sublayers 110. In the example shown in FIGs.4A-4E, rastering 400 is depicted as occurring in a single sublayer 110A of the plurality of sublayers 110 with a qubit launched from the horizontal launch layer 112 traveling along a path 411. While FIGs. 4A-4E depict the rastering 400 as time steps, the ancilla qubits 412 undergoing rastering move at a constant velocity after acceleration 402 and prior to deceleration 410.

[0142] In some embodiments, and as shown in the example of FIG.4A, the horizontal launch layer 112 stores ancilla qubits 412. The single sublayer 110A also stores data qubits 414 trapped in shallow potential wells 204 of the shallow optical tweezer array 224. Acceleration 402 includes accelerating at least one ancilla qubit 412 in the horizontal launch layer 112 to, in some embodiments, a constant velocity along the path 411.

[0143] In some embodiments, the ancilla qubits 412 may be accelerated by lattice detuning and / or applied 7t-pulses, which will be discussed in connection with FIGs.5A-5B,- 24 - #14460931v5Attorney Docket No.: H0776.70195WO00respectively. The first SLM 2002 may be configured to generate a mobile optical trap (e.g., a deep optical trap of the deep optical trap array) used to accelerate the ancilla qubits 412. After the ancilla qubit is loaded into the mobile optical trap, the first AOD 2008 may control a spatial position of the mobile optical trap to move the ancilla qubit. The first laser 2004 may additionally be configured to apply coherent 7t-pulses to ancilla qubits 412 trapped in the deep optical tweezer arrays generated by the first SLM 2002.

[0144] FIG. 4B shows a first illuminated entanglement 404, wherein a first ancilla qubit 412A and a first data qubit 414A undergo a first entanglement 416. To cause the first entanglement 416, the first AOD 2008 moves the first ancilla qubit 412A along the path 411 using the mobile optical trap. The path 411 passes through blockade radii of the data qubits 414 trapped in the shallow optical tweezer array 224. When the first ancilla qubit 412A travels along the path 411 and enters a blockade radius of the first data qubit 414A, the entangling laser 2118 illuminates the single sublayer 110A with an entangling beam 418. The entangling beam 418 entangles the first ancilla qubit 412A and the first data qubit 414A when the first ancilla qubit 412A is within the blockade radius of the first data qubit 414A. This entanglement causes the application of a quantum operation to the first ancilla qubit 412A and the first data qubit 414A.

[0145] After the first illuminated entanglement 404, the first ancilla qubit 412A is further moved along the path 411, as shown in FIG.4C depicting the displacement 406. The first ancilla qubit 412A may be further displaced by the movement of the mobile optical trap by the first AOD 2008.

[0146] FIG. 4D shows a second illuminated entanglement 408, wherein the first ancilla qubit 412A and a second data qubit 414B undergo a second entanglement 420. As in the first illuminated entanglement 404, when the first ancilla qubit 412A travels along the path 411 and enters a blockade radius of the second data qubit 414B, the entangling laser 2118 illuminates the single sublayer 110A with an entangling beam 418. The entangling beam 418 entangles the first ancilla qubit 412A and the second data qubit 414B when the first ancilla qubit 412A is within the blockade radius of the second data qubit 414B.

[0147] FIG. 4E shows the deceleration 410, wherein the horizontal launch layer 112 receives the first ancilla qubit 412A. The deep optical lattice array moves the first ancilla qubit 412A to the horizontal launch layers 112 before decelerating. In some embodiments, a reverse coherent 7t-pulse may be applied to the first ancilla qubit 412A to decelerate the- 25 - #14460931v5Attorney Docket No.: H0776.70195WO00first ancilla qubit 412A. Alternatively or additionally, the first laser 2004 may detune the deep optical lattice to decelerate the first ancilla qubit 412A. After the first ancilla qubit 412A has decelerated, the mobile optical trap may lower the first ancilla qubit 412A into the horizontal launch layer 112.

[0148] In some embodiments, the data qubits 414 proximate to a path of a given ancilla qubit 412 may be referred to as a data register, and moving ancilla qubits 412 may be referred to as an ancilla bus. It should be appreciated that while FIGs.4A-4E depict ancilla qubits 412 moving horizontally along a single sublayer 110, similar techniques may be used to launch, entangle, and decelerate ancilla qubits 412 from the vertical launch layer 102 through the distillation layers 104 and / or the computation layer 108 to be decelerated and captured by the readout layer 106 in some embodiments.

[0149] In various embodiments, the motion speed of the ancilla qubits 412 is such that the ancilla qubits 412 may traverse the distillation layers in a length of time on the order of hundreds of f s. Ancilla qubits 412 are pre-accelerated to approximately 10-100 m / s, and fast Rydberg gates may be applied without stopping the motion of the ancilla qubits 412. As compared to alternative methods relying on piecewise motion of atoms, this provides speed-ups of over 100-fold, eliminates transferring of atomic qubits between optical potentials, and allows very cold data in shallow potential wells 204.

[0150] Methods are provided herein for working with large 2D and / or 3D arrays where operations in the bulk, and information extracted from the bulk, is rapidly executed through fast-moving read / write ancilla qubits 412 and dynamically steered entangling zones. In some embodiments, readout of the data qubits 414 is realized via ancilla qubits 412. Therefore, once the data qubit 414 is placed in the arrays, the data qubits 414 do not have to be imaged and / or moved again, and computation may be carried out using the ancilla qubits 412.

[0151] FIGs. 5A-5B show examples of acceleration methods of ancilla qubits 412 in the architecture 100 during operation, including array detuning 500 and 7T-pulses 510. FIG.5A depicts optical tweezer detuning 500 during ancilla qubit 412 movement. The optical tweezer detuning 500 may be performed by detuning optical tweezers 502 storing ancilla qubits 412 relative to an optical lattice 504. In the example shown in FIG. 5A, the optical tweezer 502 waves are detuned by a factor of 100, resulting in ancilla qubit 412 motion speeds of 40 m / s with 10 f s Rydberg gates. In some embodiments, this optical tweezer array detuning 500 displaces the ancilla qubits 412 by 200 f m.- 26 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0152] FIG. 5B depicts n -pulses 510 being applied to the ancilla qubit 412, including forward n -pulses 512 and backward 7T-pulses 514, to cause acceleration and / or deceleration of the ancilla qubit 412. In the example shown in FIG.5B, the n -pulses 510 are applied for 10 ps, resulting in the ancilla qubits 412 achieving motion speeds of 40 m / s with 65 ns Rydberg gates. In some embodiments, the n -pulses 510 displaces the ancilla qubits 412 by 1 pm. Notably, 7T-pulses 510 may be applied in alternating directions, including the forward 7T -pulses 512 and the backward 7T-pulses 514.

[0153] In some embodiments, the first SLM 2002 generates the optical tweezers 502, and the first laser 2004 is configured to detune the optical lattice 504. In some embodiments, the first AOD 2008 controls the position of the optical lattice 504. The second laser 2010 may be configured to apply forward 7t-pulses 512 and backward 7t-pulses 514.

[0154] Ancilla qubits may be accelerated at high speeds, according to some embodiments. Atoms may be launched via lattices in atom interferometry experiments at approximately 40 m / s in order to be used in 100 m droptowers. A challenge is here doing this over a much shorter “runway” and thereby needing much higher accelerations. The maximum acceleration a given ancilla qubit can experience is determined by the slope of the optical trap, which is approximately equal to the trap depth on the scale of several hundred nanometers, according to some embodiments. With laser powers of approximately 1 mW per atom, but approximately 50 THz detuned to preserve coherence, a trap depth of approximately 20 MHz may be achieved, according to some embodiments.

[0155] However, because the accelerating potential does not need to preserve coherence, a detuning that is smaller by a factor of approximately 100 to 1000 may be feasible in some embodiments. As an example, a laser power approximately equal to 1 mW per atom may achieve trap depths of up to 10 GHz and corresponding accelerations up to 4 X 108m / s2. Such acceleration may result in 40 m / s ancilla qubit velocities in 100 ns and over a distance of 2 pm. Accelerations of approximately 4 X 106m / s2may be reached with the aforementioned techniques, and result in ancilla velocities equal to approximately 40 m / s in 10 ps and over a distance of 200 pm. Appling resonant 7T-pulses to ancilla qubits from alternating directions may also achieve to similar acceleration values.

[0156] Depending on the atomic species of the ancilla qubits, an accelerating potential may also “pin” the atom in a chosen state such as the |2, +2) state of Rubidium under circularly polarized optical tweezer / lattice light. Near-resonant scattering may cause - 27 - #14460931v5Attorney Docket No.: H0776.70195WO00heating but may benefit operation of embodiments described herein: during these timescales, the qubits may scatter less than 1 photon on average. Each photon also may only cause a relatively small amount of heat in a deep potential, and the displaced distance from time spent in the excited state while scattering the photon leads to negligible heating.

[0157] In some embodiments, the ancilla qubit is not “launched” with optical tweezer potentials. The ancilla may be maintained and / or guided in the optical tweezer and / or lattice optical potential. Thus, the accelerated ancilla qubit’s position is well-known, just as well as the ancilla qubit’s position when static in an array. In some embodiments, conventional electronics may lead to approximately 1 ns timing resolution, with an approximately 40 nm jitter in the atom position.

[0158] FIG. 6 is a graph 600 of the velocity of an ancilla qubit of FIGs. 4A-4E over time with a corresponding schematic 610 of applied quantum gates. Both the graph 600 and schematic 610 are plotted on a same time scale denoted by an x-axis for each. The schematic 610 includes labels identifying Hadamard gates 612 and entangling gates 614 applied to the ancilla qubits 412 of the graph 600 as the ancilla qubits 412 travel at a constant velocity.

[0159] In read / write architecture, qubit coherence may not need to be preserved while accelerating and / or decelerating. However, qubit coherence is preserved while the ancilla qubits 412 move at constant velocity. In quantum computing, constant velocity may be considered a change reference frame for the atom and approximated as the ancilla qubit being stationary. This approximation enables the architecture 100 to execute single-qubit and two-qubit control as if the ancilla qubit 412 is moving.

[0160] In some embodiments, a motion speed of 40 m / s is a target for motion speeds and is over 100-fold faster than typical motion speeds. In some embodiments, ancilla qubits traveling at 40 m / s with a gate lasting 100 ns applied (corresponding to laser power for a 99.9% fidelity gate) would correspond to the atom moving ±2 j m relative to another atomic qubit, during which time it would be comfortably within the Rydberg blockade radius of the data qubit 414. In some embodiments with 100 ns gates, and cold atoms (i.e., approximately motional ground state) in 100-fold shallower potentials (e.g., approximately 10 kHz trap frequency), the probability of motional heating is le-6per gate. This means that the data qubit trap may not need to be pulsed off during gates, which simplifies trapping large arrays with a single laser, as now the traps do not need to be all pulsed off just for gates on a subarray.- 28 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0161] In some embodiments, information storage is separated from gates and readout. Quantum circuits may be programmed by pulse timing. Because pulses are applied while the ancilla qubits 412 are at constant speed during the traversal of the array, accelerating potentials do not need to preserve qubit coherence and can be near-resonant.

[0162] FIG. 7 shows a flowchart depicting a method 700 for performing quantum information processing operation using an ancilla bus in a quantum computer. The method 700 may be implemented using a suitable quantum computing architecture (e.g., architecture 100) and / or quantum computing apparatus (e.g., apparatus 1900) in combination with one or more classical computing devices (e.g., FPGAs, classical circuitry, personal or rack-based computers, etc.) configured to control elements of the quantum computing architecture and / or apparatus.

[0163] In some embodiments, the method 700 starts with block 702, in which a first mobile optical trap is generated. For example, the first mobile optical trap may be generated by the first SLM 2002 and the first laser 2004.

[0164] In some embodiments, the method 700 may proceed to block 704, in which an ancilla qubit of a first plurality may be loaded into the first mobile optical trap. For example, the fifth AOD 2202 and / or the sixth AOD 2204 may transport a one ancilla qubit of the first plurality from the vertical launch layer 102 into the first mobile optical trap. Alternatively or additionally, it should be appreciated that the method 700 may be used to move ancilla qubits from the horizontal launch layers 112 along an x- or y-direction across the computation layer 108.

[0165] In some embodiments, the method 700 may proceed to block 706, in which the ancilla qubit loaded in the first mobile optical trap may be moved through an array of optical traps. For example, the first AOM 2006 may cause the mobile optical trap to move in a spatial direction, thereby moving the one ancilla qubit of the first plurality

[0166] In some embodiments, the array of optical traps may be configured to store a first plurality of data qubits and a second plurality of data qubits. The first plurality of data qubits may be trapped in the distillation layer 104. The second plurality of data qubits may be trapped in the computation layer 108. The first mobile optical trap may move the one ancilla qubit of the first plurality along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and / or second plurality. The one- 29 - #14460931v5Attorney Docket No.: H0776.70195WO00ancilla qubit may be accelerated using the first SLM 2002 and / or the first AOD 2008, as discussed herein.

[0167] In some embodiments, the method 700 may proceed to block 708, in which a sequence of gates (e.g., entangling gates) may be applied between the one ancilla qubit and data qubits stored in the array of optical traps. A gate may be applied when the one ancilla qubit is within a blockade radius of one of the data qubits. To cause application of the gate, the entangling laser 2118 may illuminate a layer (e.g., a sublayer 110 or the computation layer 108) while the one ancilla qubit is within a blockade radius of the one data qubit. In some embodiments, the entangling laser 2118 illuminates a whole of the optical trap with the entangling beam 418, but the one ancilla qubit only entangles with a data qubit when and if the one ancilla qubit passes through the blockade radius of a data qubit.

[0168] In some embodiments, the method 700 may proceed to block 710, in which the one ancilla qubit is transferred from the first mobile optical trap into the readout layer (e.g., readout layer 106). For example, the fifth AOD 2202 and / or the sixth AOD 2204 may transfer the one ancilla qubit of the first plurality from the first mobile optical trap into the readout layer 106 by transferring the one ancilla qubit into a shallow optical trap in the readout layer 106.

[0169] In some embodiments, the method 700 may proceed to block 712, in which the readout layer 106 is illuminated. For example, the readout layer 106 may be illuminated by a readout beam generated by the readout laser 2122.

[0170] In some embodiments, the method 700 may then proceed to block 714, in which an image is captured of the one ancilla qubit. The image may be captured by, for example, CMOS camera 1908 or another suitable imaging device. The captured image may then be used to determine a quantum state of the one ancilla qubit and / or any other ancilla qubits present in the readout layer 106.

[0171] FIGs. 8-12D depict illustrative quantum computing architectures suitable for particular quantum computations tasks. FIG. 8 depicts an architecture 800 configured for fast stability measurements, in accordance with some embodiments of the technology described herein. The architecture 800 shown in FIG. 8 includes a launch lattice 802, an array of codes 804, and a readout lattice 806. In the embodiment of FIG. 8, the array of codes 804 includes a plurality of code arrays 804A-804E with data qubits 414 trapped in- 30 - #14460931v5Attorney Docket No.: H0776.70195WO00potential wells. In some embodiments, each of the plurality of code arrays 804A-804E may encode quantum information in a code (e.g., a surface code, a tone code, etc.).

[0172] In some embodiments, the launch lattice 802 is configured to trap ancilla qubits 412 in potential wells. In the embodiment shown in FIG. 8, a first entangling gate 806A is applied to a first code array 804A and a second entangling gate 806B is applied to a fourth code array 804D. In other embodiments, any number of entangling gates may be applied to the code arrays 804N within the array of codes 804.

[0173] FIG. 9 depicts an architecture 900 configured for fast routing. The architecture 900 shown in FIG. 9 includes a first launch lattice 902A, a second launch lattice 902B, a first readout lattice 904A, a second readout lattice 904B, and a data lattice 906, in accordance with some embodiments of the technology described herein.

[0174] FIG. 10 depicts an architecture 1000 configured for cavity array readout. The architecture 1000 shown in FIG. 10 includes a launch array 1002, data arrays 1004, and a readout array 1006 positioned between a pair of optical cavity arrays 1008, in accordance with some embodiments of the technology described herein.

[0175] FIG. 11 depicts an architecture 1100 for heralded long-range entanglement. The architecture 1100 shown in FIG.11 includes a first module 1102 and a second module 1104. The first module 1102 includes a launch array 1106 and a first data array 1108. The second module 1104 includes a second data array 1110 and a readout array. The first and second module 1102, 1104 are separated by a distance 1114. In the embodiment in FIG. 11, the distance is approximately equal to 5 cm, though it should be appreciated that the distance 1114 could be less than or greater than 5 cm (e.g., 1 cm, 2.5 cm, 3 cm, 4 cm, 7.5 cm, 10 cm, etc.).

[0176] FIG. 12A-12D depict time steps of parallel Greenberger-Home-Zellinger (GHZ) state creation using the dynamic zone architecture 1202 depicted. The method of parallel GHZ state creation as shown includes initialization 1210, a first entanglement 1220A, a second entanglement 1220B, and readout 1230, with time steps for causing entanglement with remaining layers between second entanglement 1220B and readout 1230 omitted for simplicity. A quantum circuit schematic 1240 adjacent the depicted time steps represents unitary transformations between qubits stored in the dynamic zone architecture 1202. The quantum circuit schematic 1240 includes quantum gates 1250 indicating unitary- 31 - #14460931v5Attorney Docket No.: H0776.70195WO00operations performed on the qubits stored in the dynamic zone architecture 1202 during parallel GHZ state creation.

[0177] In some embodiments, the dynamic zone architecture 1202 as shown in FIG.12A includes the vertical launch layer 102 storing the ancilla qubits 412, the distillation layer 104 storing data qubits 414 (not shown), and the readout layer 106.

[0178] In some embodiments, the first entanglement 1220A shown in FIG. 12B starts when a mobile optical trap moves the ancilla qubits 412 from the vertical launch layer 102 to a first sublayer 110A. The first sublayer 110A is illuminated by the entangling beam 418, which entangles ancilla qubits 412 in the mobile optical trap with data qubits 414 in the distillation layers 104 wherever the ancilla qubit 412 is within the blockade radius of a given data qubit 414.

[0179] In some embodiments, the second entanglement 1220B shown in FIG. 12C starts when the mobile optical trap moves the ancilla qubits 412 from the first sublayer 110A to a second sublayer HOB and subsequently applying a second quantum gate 1250B, as described in FIG. 12B.

[0180] In some embodiments, the mobile optical trap continues to move ancilla qubits 412 through each sublayer 110 of the distillation layer 104, at which the ancilla qubits 412 have a quantum gate 1250 applied by the entangling beam 418 as described above until the ancilla qubits 412 are moved to the Nth sublayer 110N.

[0181] In some embodiments, the readout 1230 shown in FIG. 12D starts after the mobile optical trap moves the ancilla qubits 412 from the Nth sublayer 110N to the readout layer 106. The fifth AOD 2202 and / or sixth AOD 2204 may then move the ancilla qubits 412 from the mobile optical trap to the readout layer 106, as shown in in FIG. 12D.

[0182] While only a first and a second entanglement 1220 A, 1220B are shown in FIGs.12B-12C, any number of entanglements 1220 may be performed. As shown in FIG. 12D, an Nth quantum gate 1250N is indicated on the quantum circuit schematic 1240, which occurs during an Nth entanglement 1220N.

[0183] FIG. 13 illustrates an illustrative method for local addressing 1300 using an accordion lattice 1302 generated by global beams 1304. In some embodiments, the global beams 1304 may be generated by the entangling laser 2118. The techniques for local addressing 1300 may be used, for example, in the dynamic zone architecture 1202 shown in FIGs. 12A-12D. In such embodiments, the global beams 1304 may be rastered over up to- 32 - #14460931v5Attorney Docket No.: H0776.70195WO00approximately 500x500 unique spots by use of a two-dimensional (2D) acousto-optical deflectors (AODs). The 2D AODs are compact and global beams 1304 may be controlled by a single master waveform generator with approximately 10-20 output ports. Although simple and compact, such a change may provide significant flexibility.

[0184] FIG. 14 illustrates an illustrative magic state distillation circuit of the dynamic zone architecture 1202 shown in FIGs. 12A-12D.

[0185] FIG. 15 illustrates fast stabilizer measurement 1500 on low-density paritycheck (LDPC) codes 1502. Leveraging the fast acceleration, and the structure of LDPC codes 1502 such as hypergraph product and Bivariate Bicycle (BB) codes, one can use the techniques provided herein to achieve fast stabilizer measurements, fast transversal gates, and fast permutations. This is useful for quantum processing with quantum LDPC (qLDPC) codes. The LDPC codes 1502 include launching zones 1504, data zones 1506, and 1508 zones. As depicted, lines depict quantum operations between zones.

[0186] FIG. 16 illustrates iterative sensing 1600 with clock atoms 1602. In this example, approximately 109 atoms are employed. However, it should be appreciated that the architectures described herein (e.g., architecture 100) may be adapted for use as an atomic clock, permitting the usage of many thousands of atoms for clocking. In some embodiments, an atomic time unit is quantified by a wavelength of light emitted by any one of the first pluralities of data qubits during a deexcitation event.

[0187] FIG. 17 is a schematic view of an illustrative optical train 1700 for generation of a three-dimensional (3D) optical tweezer array. In some embodiments, a 3D interference pattern produced by the optical train 1700 may accommodate over 100 resolvable layers for a 100 x 100 array. FIG. 18 is an illustrative Talbot re-interference pattern 1800 generated by the optical train 1700 of FIG. 17.

[0188] In some embodiments, an array generated by the illustrative Talbot reinterference pattern 1800 may accommodate at least 105 atoms when used as a 3D lattice clock. Certain configurations provided herein are suitable for up to 109 sites. When used for quantum computation, an illustrative embodiment fills 1 / 8000 of the lattice sites. Altogether, these techniques can be used for creating approximately 100 planes separated by approximately 10-30 pm. These are sufficiently separated such that an individual plane can be resolved without disturbing the neighboring planes, both for Raman and / or Rydberg addressing from the side, as well as for placing arrays. Even without reduced tweezer power- 33 - #14460931v5Attorney Docket No.: H0776.70195WO00per trap, this leads to greater than one million well- separated (e.g., spaced by approximately 5-10 um) tweezer sites in an approximately 1 mm x 1 mm x 1 mm region, addressable with existing commercial optics. Reducing tweezer depth as well can allow for approximately one billion manipulated sites with dimensions of approximately 5 mm x 5 mm x 5 mm.

[0189] FIG. 24 is a level diagram showing key87Rb atomic levels used in illustrative embodiments. The |0), 11) qubit states refer to the mp= 0 clock states of87Rb, and |r) is a Rydberg state used for generating entanglement between qubits. The Rydberg excitation scheme from 11) to |r) is composed of a two-photon transition driven by a 420-nm laser and a 1013-nm laser. A DC magnetic field of B = 8.56 is applied in some embodiments. Example

[0190] In combination, the apparatus 1900 shown in FIG. 19 may be used for quantum computing by employing optical trapping. Optical trapping of neutral atoms is a powerful technique for isolating atoms in vacuum. Atoms are polarizable, and the oscillating electric field of a light beam induces an oscillating electric dipole moment in the atom. The associated energy shift in an atom from the induced dipole, averaged over a light oscillation period, is called the AC Stark shift. Based on the AC Stark shift induced by light that is detuned (i.e., offset in wavelength) from atomic resonance transitions, atoms are trapped at local intensity maxima (for red detuned, that is, longer wavelength trap light), because the atoms are attracted to light below the resonance frequency. The AC Stark shift is proportional to the intensity of the light. Thus, the shape of the intensity field is the shape of an associated atom trap. Optical tweezers utilize this principle by focusing a laser to a micron-scale waist, where individual atoms are trapped at the focus. Two-dimensional (2D) arrays of optical tweezers are generated by, for example, illuminating a spatial light modulator (SLM), which imprints a computer- generated hologram on the wavefront of the laser field. The 2D array of optical tweezers overlaps with a cloud of laser-cooled atoms in a magneto-optical trap (MOT). The tightly focused optical tweezers operate in a “collisional blockade” regime, in which single atoms are loaded from the MOT, while pairs of atoms are ejected due to light-assisted collisions, ensuring that the optical tweezers are loaded with at most single atoms, but the loading is probabilistic, such that the trap is loaded with a single atom with a probability of about 50-60%.

[0191] To prepare deterministic atom arrays, a real-time feedback procedure identifies the randomly loaded atoms and rearranges them into pre-programmed geometries. Atom- 34 - #14460931v5Attorney Docket No.: H0776.70195WO00rearrangement requires moving atoms in optical tweezers which can be smoothly steered to minimize heating, by using, for example, acousto-optic deflectors (AODs) to deflect a laser beam by a tunable angle which is controlled by the frequency of an acoustic waveform applied to the AOD crystal. Dynamic tuning of the acoustic frequency translates into smooth motion of an optical tweezer. A multi-frequency acoustic wave creates an array of laser deflections, which, after focusing through a microscope objective, forms an array of optical tweezers with tunable position and amplitude that are both controlled by the acoustic waveform. Atoms are rearranged by using an additional set of dynamically moving optical tweezers that are overlaid on top of the SLM optical tweezer array.

[0192] Optical tweezer arrays constitute a powerful and flexible way to construct large scale systems composed of individual particles. Each optical tweezer traps a single particle, including, but not limited to, individual neutral atoms and molecules for applications in quantum technology. Loading individual particles into such optical tweezer arrays is a stochastic process, where each optical tweezer in the system is filled with a single particle with a finite probability p<l, for example p~0.5 in the case of many neutral atom optical tweezer implementations. To compensate for this random loading, real-time feedback may be obtained by measuring which optical tweezers are loaded and then sorting the loaded particles into a programmable geometry. This may be performed by moving one particle at a time, or in parallel.

[0193] Parallel sorting may be achieved by using two acousto-optic deflectors (AODs) to generate multiple optical tweezers that can pick up particles from an existing particletrapping structure, move them simultaneously, and release them somewhere else. This can include moving particles around within a single trapping structure (e.g., optical tweezer array) or transporting and sorting particles from one trapping system to another (e.g., between one optical tweezer array and another type of optical / magnetic trap). This sorting is flexible and allows programmed positioning of each particle. Each movable trap is formed by the AODs and its position is dynamically controlled by the frequency components of the radiofrequency (RF) drive field for the AODs. Since the RF drive of the AODs can be controlled in real time and can include any combination of frequency components, it is possible to generate any grid of traps (such as a line of arbitrarily positioned traps), move the rows or columns of the grid, and add or remove rows and columns of the grid, by- 35 - #14460931v5Attorney Docket No.: H0776.70195WO00changing the number, magnitude, and distribution of the frequency components in the RF drive fields of the AODs.

[0194] In an illustrative embodiment, an optical tweezer array is created using a liquid crystal on silicon spatial light modulator (SLM), which can programmatically create flexible arrangements of optical tweezers. These optical tweezers are fixed in space for a given experimental sequence and loaded stochastically with individual atoms, such that each optical tweezer is loaded with probability p ~ 0.5. A fluorescent image of the loaded atoms is taken, to identify in real-time which optical tweezers are loaded and which are empty.

[0195] After detecting which optical tweezers are loaded, movable optical tweezers overlapping the optical tweezer array can dynamically reposition atoms from their starting locations to fill a target arrangement of traps with near-unity filling. The movable optical tweezers are created with a pair of crossed AODs. These AODs can be used to create a single moveable trap which moves one atom at a time to fill the target arrangement or to move many atoms in parallel.

[0196] In this respect, it should be appreciated that one implementation of the embodiments described herein comprises at least one computer-readable storage medium (e.g., RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible, non-transitory computer-readable storage medium) encoded with a computer program (i.e., a plurality of executable instructions) that, when executed on one or more processors, performs the abovediscussed functions of one or more embodiments. The computer-readable medium may be transportable such that the program stored thereon can be loaded onto any computing device to implement aspects of the techniques discussed herein. In addition, it should be appreciated that the reference to a computer program which, when executed, performs any of the abovediscussed functions, is not limited to an application program running on a host computer. Rather, the terms computer program and software are used herein in a generic sense to reference any type of computer code (e.g., application software, firmware, microcode, or any other form of computer instruction) that can be employed to program one or more processors to implement aspects of the techniques discussed herein.

[0197] It will be apparent that example aspects, as described above, may be implemented in many different forms of software, firmware, and hardware in the- 36 - #14460931v5Attorney Docket No.: H0776.70195WO00implementations illustrated in the figures. Further, certain portions of the implementations may be implemented as a “module” that performs one or more functions. This module may include hardware, such as a processor, an application- specific integrated circuit (ASIC), or a field-programmable gate array (FPGA), or a combination of hardware and software.

[0198] The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects as described above. Additionally, it should be appreciated that according to one aspect, one or more computer programs that when executed perform methods of the present disclosure need not reside on a single computer or processor but may be distributed in a modular fashion among a number of different computers or processors to implement various aspects of the present disclosure.

[0199] Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0200] Also, data structures may be stored in computer-readable media in any suitable form. For simplicity of illustration, data structures may be shown to have fields that are related through location in the data structure. Such relationships may likewise be achieved by assigning storage for the fields with locations in a computer-readable medium that convey relationship between the fields. However, any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish relationship between data elements.

[0001] When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers.

[0002] Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack- mounted computer, a desktop computer, a laptop computer, or a tablet computer, as non-limiting examples. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities,- 37 - #14460931v5Attorney Docket No.: H0776.70195WO00including a Personal Digital Assistant (PDA), a smartphone, a tablet, or any other suitable portable or fixed electronic device.

[0003] Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible formats.

[0004] Such computers may be interconnected by one or more networks in any suitable form, including a local area network or a wide area network, such as an enterprise network, and intelligent network (IN) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks.

[0005] Having thus described several aspects and embodiments of the technology set forth in the disclosure, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the technology described herein. For example, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the embodiments described herein. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation many equivalents to the specific embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described. In addition, any combination of two or more features, systems, articles, materials, kits, and / or methods described herein, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the scope of the present disclosure.- 38 - #14460931v5Attorney Docket No.: H0776.70195WO00

[0006] Also, as described, some aspects may be embodied as one or more methods. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0007] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0008] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0009] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0010] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than- 39 - #14460931v5Attorney Docket No.: H0776.70195WO00B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0011] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0012] The use of “coupled” or “connected” is meant to refer to circuit elements, or signals, which are either directly linked to one another or through intermediate components. Elements that are not “coupled” or “connected” are “decoupled” or “disconnected.” The terms “approximately,” “substantially,” and “about” may be used to mean within ±20% of a target value in some embodiments, within ±10% of a target value in some embodiments, within ±5% of a target value in some embodiments, within ±2% of a target value in some embodiments, and / or within ±1% of a target value in some embodiments. The terms “approximately,” “substantially,” and “about” may include the target value.- 40 - #14460931v5

Claims

1. Attorney Docket No.: H0776.70195WO00CLAIMSWhat is claimed is:

1. A quantum computer, comprising:an array of optical traps configured to store atomic qubits in respective optical traps of the array, the array comprising:a vertical launch layer configured to store a first plurality of ancilla qubits; a distillation layer configured to store a first plurality of data qubits;a computation layer configured to store a second plurality of data qubits; a first mobile optical trap configured to move one ancilla qubit of the first plurality from the vertical launch layer through the array along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and second plurality; anda readout layer configured to receive the one ancilla qubit after the one ancilla qubit is moved through the distillation layer and the computation layer;at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the first plurality and ones of the sequence of data qubits of the first and second plurality while the first mobile optical trap moves the one ancilla qubit of the first plurality along the first path and when the one ancilla qubit of the first plurality is within the blockade radius of a data qubit of the sequence of data qubits; a camera configured to capture an image of the one ancilla qubit of the first plurality during entanglement; andat least one readout laser configured to illuminate the one ancilla qubit of the first plurality subsequent to the one ancilla qubit being loaded into the readout layer.

2. The quantum computer of claim 1, wherein the array of optical traps further comprises a horizontal launch layer configured to store a second plurality of ancilla qubits.

3. The quantum computer of claim 2, wherein the array of optical traps further comprises a second mobile optical trap configured to move one ancilla qubit of the second- 41 - #14460931v5Attorney Docket No.: H0776.70195WO00plurality from the vertical launch layer along a second path, the second path passing within a blockade radius of each of a sequence of data qubits of the second plurality.

4. The quantum computer of claim 3, wherein the at least one entangling laser is configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the second plurality and ones of the sequence of data qubits of the second plurality while the second mobile optical trap moves the one ancilla qubit of the second plurality along the second path and when the one ancilla qubit of the second plurality is within the blockade radius of a data qubit of the sequence of data qubits.

5. The quantum computer of claim 4, wherein the arrays of optical traps comprise optical tweezer spots generated by Talbot re-interference.

6. The quantum computer of claim 2, wherein the ancilla qubits of the first and second plurality are accelerated by an ancilla acceleration system, the ancilla acceleration system comprising:a first spatial light modulator configured to generate 2D lattice arrays using a first laser;a first acousto-optical modulator configured control the 2D lattice arrays generated by the first laser;a first acousto-optical deflector configured to control the horizontal launch layer in the array using a second laser; anda first polarizing beam splitter configured to combine laser beams generated by the first and second laser.

7. The quantum computer of claim 6, wherein the first and / or second lasers are near-resonant lasers.

8. The quantum computer of claim 7, wherein the first and / or second lasers are 10-100 GHz detuned.- 42 - #14460931v5Attorney Docket No.: H0776.70195WO009. The quantum computer of claim 2, wherein qubit control is performed by a system of control lasers, the system comprising:a second acousto-optical deflector configured to direct a Raman single-qubit control beam;a third acousto-optical deflector configured to direct an entangling beam generated by the at least one entangling laser;a fourth acousto-optical deflector configured to direct a readout beam generated by the at least one readout laser;a second polarized beam splitter configured to combine the Raman single-qubit control beam and the readout beam; anda first dichroic mirror configured to filter the Raman single-qubit control beam, the readout beam, and the entangling beam.

10. The quantum computer of claim 9, wherein the entangling beam is a Rydberg two-qubit entangling beam.

11. The quantum computer of claim 9, wherein the Raman single-qubit control beam uses an amplitude modulated laser controlled by microwaves.

12. The quantum computer of claim 10, wherein the Rydberg two-qubit entangling beam uses a high-power laser stabilized to an ultra-low thermal expansion cavity.

13. The quantum computer of claim 12, wherein the readout beam uses a laser locked to an atomic resonance of the atomic qubits of the plurality of atomic qubits.

14. The quantum computer of claim 13, wherein the system of control lasers further comprises a plurality of acousto-optical modulators to execute timing control of the plurality of lasers.

15. The quantum computer of claim 9, wherein the second acousto-optical deflector is configured to move the one ancilla qubit of the first plurality across the distillation layer and the computation layer.- 43 - #14460931v5Attorney Docket No.: H0776.70195WO0016. The quantum computer of claim 2, wherein the array of optical traps are controlled by an array trapping system, the system comprising:a fifth and sixth acousto-optical deflector configured to control plane-by -plane loading and / or filling, wherein:the fifth acousto-optical deflector controls a third laser beam; and the sixth acousto-optical deflector controls a fourth laser beam;a third polarized beam splitter configured to combine the third and fourth laser beam; a focus tunable lens configured to focus the combined third and fourth laser beams; a second spatial light modulator configured to perform static 3D optical tweezer generation using a fifth laser; anda second dichroic mirror configured to filter the combined third, fourth, and fifth laser beam.

17. The quantum computer of claim 16, wherein the fifth laser beam is generated by a high-power laser operating at approximately 100W.

18. The quantum computer of claim 16, wherein the second spatial light modulator is configured to store the pluralities of data and ancilla qubits in shallow optical tweezer arrays.

19. The quantum computer of claim 18, wherein the second spatial light modulator is configured to generate static 3D optical tweezers using Talbot re-interference.

20. The quantum computer of claim 18, wherein the shallow optical tweezer arrays have a potential of less than or equal to 1 microwatt per optical tweezer.

21. The quantum computer of claim 2, wherein components of the quantum computer are controlled by a system of control electronics, the system comprising:acousto-optical modulator drivers;a global microwave oscillator (LO) configured to generate low noise oscillations; an in-phase and quadrature (IQ) controller configured to control signals produced by the LO; and- 44 - #14460931v5Attorney Docket No.: H0776.70195WO00a master field-programmable gate array (FPGA) configured to control operations in the system of control electronics.

22. The quantum computer of claim 21, wherein the master FPGA is further configured to transmit ten pairs of X / Y acousto-optical deflector signals to control a plurality of acousto-optical deflectors of the quantum computer.

23. The quantum computer of claim 22, wherein the master FPGA is further configured to transmit between 20 and 30 transistor-transistor logic signals to the acousto-optical modulator drivers.

24. The quantum computer of claim 23, wherein the acousto-optical drivers are configured to execute precise acousto-optical timing control in response to the transistortransistor logic signals.

25. The quantum computer of claim 23, wherein the master FPGA is further configured to transmit two 200MHz signals to the IQ controller.

26. The quantum computer of claim 25, wherein the IQ controller is configured to execute Ramin qubit control in response to the two 200MHz signals.

27. The quantum computer of claim 1, wherein the distillation layer includes a plurality of sublayers.

28. The quantum computer of claim 27, wherein a deep optical tweezer array is configured to move the one ancilla qubit of the first plurality sequentially through the plurality of sublayers.

29. The quantum computer of claim 2, wherein the first mobile optical trap is configured to move the one ancilla qubit of the first plurality at a constant speed along the first path.- 45 - #14460931v5Attorney Docket No.: H0776.70195WO0030. The quantum computer of claim 29, wherein the second mobile optical trap is configured to move the one ancilla qubit of the second plurality at a constant speed along the second path.

31. The quantum computer of claim 30, wherein the constant speed is between lOm / s and lOOm / s.

32. The quantum computer of claim 2, wherein the ancilla and / or data qubits comprise alkali metals.

33. The quantum computer of claim 32, wherein the ancilla and / or data qubits comprise atoms that are alkaline-earth metals.

34. The quantum computer of claim 33, wherein the ancilla and / or data qubits comprise atoms that are alkali- and / or alkaline-earth metals.

35. A method for performing quantum information processing operation using an ancilla bus in a quantum computer, the method comprising:generating a first mobile optical trap;loading, from a vertical launch layer into the first mobile optical trap, one ancilla qubit of a first plurality;moving, by the first mobile optical trap, the one ancilla qubit of the first plurality through an array of optical traps configured to store a first and second plurality of data qubits in a respective optical trap of the array, along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and / or second plurality; at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the first plurality and ones of the sequence of data qubits of the first and second plurality while the first mobile optical trap moves the one ancilla qubit of the first plurality along the first path and when the one ancilla qubit of the first plurality is within the blockade radius of a data qubit of the sequence of data qubits; capturing an image of the one ancilla qubit of the first plurality during illumination;- 46 - #14460931v5Attorney Docket No.: H0776.70195WO00transferring the one ancilla qubit of the first plurality from the first mobile optical trap into a readout layer; andilluminating the readout layer with a readout laser.

36. The method of claim 35, wherein optical tweezer spots comprising the array of optical traps are generated by Talbot re-interference.

37. The method of claim 35, wherein moving the first plurality of ancilla qubits through the array comprises:moving, by the first mobile optical trap, the first plurality of ancilla qubits through a distillation layer; andmoving, by the first mobile optical trap, the ancilla qubits through a computation layer, the computation layer loaded with data qubits of a second plurality.

38. The method of claim 37, wherein the distillation layer comprises a plurality of sublayers.

39. The method of claim 37, wherein the method further comprises:generating a second mobile optical trap;loading, from a horizontal launch layer, a one ancilla qubit of the second plurality into the second mobile optical trap;moving, by the second optical trap, the one ancilla qubit of the second along a second path, the second path passing within a blockade radius of each of a sequence of data qubits of the second plurality stored in the computational layer;entangling the second plurality of data qubits and the one ancilla qubit of the second plurality;at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the second plurality and ones of the sequence of data qubits of the second plurality while the second mobile optical trap moves the one ancilla qubit of the second plurality along the second path and when the one ancilla qubit of the second plurality is within the blockade radius of a data qubit of the sequence of data qubits;- 47 - #14460931v5Attorney Docket No.: H0776.70195WO00capturing an image of the one ancilla qubit of the second plurality during illumination;transferring, from the computational layer, the one ancilla qubit of the second plurality into the second mobile optical trap; andtransferring, from the second mobile optical trap, the one ancilla qubit of the second plurality into the horizontal launch layer.

40. The method of claim 39, wherein storing the pluralities of ancilla and data qubits comprises storing the pluralities of ancilla and data qubits in shallow optical tweezer arrays.

41. The method of claim 40, wherein moving, imaging, and / or storing the one ancilla qubit of the first and second plurality comprises using deep optical tweezer arrays.

42. The method of claim 40, wherein measuring the one ancilla qubit of the first and / or second plurality comprises determining a state of the one ancilla qubit of the first and / or second plurality.

43. The method of claim 39, wherein the method further comprises replacing lost qubits in any of the vertical launch layer, the distillation layer, the computational layers, the horizontal launch layer, and the readout layer by transferring atoms stored in a bulk array in the quantum computer.

44. The method of claim 43, wherein atoms stored in the array are continuously supplied via a lattice conveyer belt configured to transport cold atoms into the quantum computer.

45. The method of claim 35, wherein entangling the one ancilla qubit of the first plurality and the data qubits of the first plurality comprises performing a transversal entangling gate.

46. The method of claim 45, wherein the plurality of qubits may be entangled to create a Greenberger-Horne-Zellinger (GHZ) state.

47. The method of claim 35, wherein the method is configured to distill magic states.- 48 - #14460931v5Attorney Docket No.: H0776.70195WO0048. An atomic clock, comprising:an array of optical traps configured to store pluralities of atomic qubits in respective optical traps of the array, the pluralities of atomic qubits comprising:a first plurality of ancilla qubits;a first plurality of data qubits; anda second plurality of data qubits;at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the first plurality and ones of the sequence of data qubits of the first and second plurality while the first mobile optical trap moves the one ancilla qubit of the first plurality along the first path and when the one ancilla qubit of the first plurality is within the blockade radius of a data qubit of the sequence of data qubits; at least one laser configured to illuminate the one ancilla qubit of the first plurality subsequent to applying the sequence of entangling gates; anda camera configured to capture an image of the one ancilla qubit of the first plurality during illumination.

49. The atomic clock of claim 48, wherein the array comprises:a vertical launch layer configured to store the first plurality of ancilla qubits;a distillation layer configured to store the first plurality of data qubits;a computation layer configured to store the second plurality of data qubits;a first mobile optical trap configured to move one ancilla qubit of the first plurality from the vertical launch layer through the array along a first path, the first path passing within a blockade radius of each of a sequence of data qubits of the first and second plurality; and a readout layer configured to receive the one ancilla qubit after the one ancilla qubit is moved through the distillation layer and the computation layer.

50. The atomic clock of claim 49, wherein the array of optical traps further comprises a horizontal launch layer configured to store a second plurality of ancilla qubits.

51. The atomic clock of claim 50, wherein the array of optical traps further comprises a second mobile optical trap configured to move one ancilla qubit of the second plurality from- 49 - #14460931v5Attorney Docket No.: H0776.70195WO00the vertical launch layer along a second path, the second path passing within a blockade radius of each of a sequence of data qubits of the second plurality.

52. The atomic clock of claim 51, wherein the at least one entangling laser configured to cause the application of a sequence of entangling gates to the one ancilla qubit of the second plurality and ones of the sequence of data qubits of the second plurality while the second mobile optical trap moves the one ancilla qubit of the second plurality along the second path and when the one ancilla qubit of the second plurality is within the blockade radius of a data qubit of the sequence of data qubits.

53. The atomic clock of claim 51, wherein the arrays of optical traps comprise optical tweezer spots generated by Talbot re-interference.

54. The atomic clock of claim 48, wherein an atomic time unit is quantified by a wavelength of light emitted by any one of the first pluralities of data qubits during a deexcitation event.- 50 - #14460931v5

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