Multi-Beam Raman Optics for Low-Crosstalk Qubit Addressing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing quantum computing systems face challenges with global addressing beams that induce idle phase errors, increase gate crosstalk, and enhance spontaneous emission, particularly when handling large arrays of trapped atomic ions.
Innovation Solution
A double individual-addressing multi-beam Raman system is implemented using symmetrical optical paths with telecentric zoom lenses and interleavers to generate matched sets of individually addressed beams from opposite directions, reducing beam spacing and sensitivity to alignment drift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If global addressing beams are used to address large arrays of trapped atomic ions, then the ability to address multiple qubits is improved, but idle phase errors increase
Solution Approach 1:
The patent divides the single global addressing beam into multiple individual beams, each targeting a specific qubit. This segmentation allows selective addressing of only the required qubits rather than illuminating all qubits globally, thereby reducing idle phase errors on non-addressed qubits while maintaining the ability to address multiple qubits simultaneously
Solution Approach 2:
The patent implements individual beams with specific local properties (direction, focus, intensity) tailored to address specific qubits. Each beam is optimized for its target qubit's location and characteristics, enabling precise local control without affecting neighboring qubits, thus reducing idle phase errors while maintaining multi-qubit addressing capability
2Productivity
If global addressing beams are used to address large arrays of trapped atomic ions, then the ability to address multiple qubits is improved, but gate crosstalk increases
Solution Approach 1:
The patent segments the global beam into multiple individually directed beams, each precisely targeted at a specific qubit. This segmentation eliminates the overlapping illumination that causes crosstalk in global addressing, allowing simultaneous multi-qubit operations without interference between gates
Solution Approach 2:
Each individual beam is optimized with specific local properties (direction, waist size, focus position) matched to its target qubit's location in the chain. This local optimization ensures that beams address only their intended qubits without spilling over to neighboring qubits, thereby reducing gate crosstalk while maintaining the ability to address multiple qubits
3Productivity
If global addressing beams are used to address large arrays of trapped atomic ions, then the ability to address multiple qubits is improved, but spontaneous emission increases
Solution Approach 1:
The patent divides the global addressing beam into multiple individual beams, each directed only at the specific qubit that requires addressing. This segmentation reduces the total volume of space illuminated by addressing beams, thereby reducing the overall spontaneous emission from the system while maintaining the ability to address multiple qubits simultaneously
Solution Approach 2:
Each individual beam is focused precisely on its target qubit with optimized local properties, minimizing the beam's spatial extent and intensity in regions away from the target. This localized addressing reduces the probability of spontaneous emission events compared to global illumination, while still enabling multi-qubit operations
4Reliability
If individual addressing beams are used to minimize crosstalk, then gate fidelity is improved, but alignment sensitivity increases
Solution Approach 1:
The patent employs asymmetric optical elements (prisms, mirrors) in the beam delivery system that are specifically designed to compensate for alignment drift. These asymmetric components create optical paths that are inherently more robust to positional variations, reducing alignment sensitivity while maintaining the precise individual beam addressing needed for high gate fidelity
Solution Approach 2:
The patent implements adjustable optical parameters (beam waist size, focus position, angle of incidence) that can be dynamically optimized to reduce alignment sensitivity. By tuning these parameters, the system maintains high gate fidelity through individual beam addressing while compensating for alignment variations, thereby reducing the practical impact of alignment sensitivity
5Measurement precision
If beam spacing is reduced to address densely packed qubits, then addressing precision is improved, but sensitivity to alignment drift increases
Solution Approach 1:
The patent implements adjustable optical parameters including beam waist size and focus position that can be dynamically optimized for different beam spacing configurations. When beam spacing is reduced for densely packed qubits, the system adjusts beam parameters to maintain addressing precision while compensating for increased sensitivity to alignment drift, thereby achieving both dense packing and robust operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system minimizes crosstalk, optimizes laser power usage, reduces phase errors on idle qubits, and decreases spontaneous emission, enhancing the fidelity of quantum operations.
Implementation Method 1
Double individual-addressing multi-beam Raman system
Implementation Method 2
a first diffractive optical element (DOE) and a second DOE. The laser source is configured to generate a single beam, the single beam is split and a portion is provided to the first DOE and the first DOE is configured to generate the first array of beams from the portion of the single beam
Implementation Method 3
the first MCM is a first multi-channel acousto-optic modulator (AOM), and the second MCM is a second multi-channel AOM
Data Source
AI summary
Aspects of the present disclosure relate generally to systems and methods for use in the implementation and/or operation of quantum information processing (QIP) systems, and more particularly, to a double individual-addressing multi-beam Raman system for use in QIP systems. A technique is described in which a first multi-channel modulator (MCM), a first telecentric zoom lens, and a first interleaver that form a first optical path of the Raman system that receives a first array of beams and adjusts the first array of beams to individually address atomic-based qubits in a chain from a first direction. Moreover, a second MCM, a second telecentric zoom lens, and a second interleaver form a second optical path of the Raman system that receives a second array of beams and adjusts the second arrays of beams to individually address the atomic-based qubits in the chain from a second direction different from the first direction.