Improvements in or related to quantum computing

Abstract

This invention provides a device and method for achieving site-specific gate control for magnetically sensitive qubits in quantum computing. [Solution] A device comprising a plurality of independent rotary gates, each rotary gate comprising a magnet that generates a magnetic field structure 10, 11 of a predetermined strength at the qubit position of the respective rotary gate, the magnetic field generating the resonance frequency of the qubit at the qubit position due to the magnetically sensitive electronic state of the qubit 15. The device also comprises a first electromagnetic field source 26-29 that generates an electromagnetic field of the resonance frequency over a predetermined period of time across the plurality of independent rotary gates. Each independent rotary gate comprises a controller 41 that independently de-resonates the qubit at a predetermined time within the predetermined period.

Description

Technical Field

[0001] The present invention relates to improvements in or related to quantum computing, and in particular to achieving site-specific gate control for magnetically sensitive qubits.

Summary of the Invention

[0002] Generally, unlike so-called "classical computing," quantum computing relies on the quantum mechanical properties of particles or substances to generate or modify data. The data may be represented by qubits or "quantum bits," which are two-state quantum mechanical systems. Unlike classical computing, qubits may be a superposition of quantum states. Another feature of quantum computing is the entanglement between qubits where the state of one particle or atom is affected by another particle or atom.

[0003] Quantum mechanical qubits can simultaneously encode information as a combination of zero and one. Such properties enable numerous complex numerical applications that have traditionally been difficult on classical computers. Examples include artificial intelligence, image processing and recognition, cryptography, or secure communication.

[0004] Within the ion hyperfine electronic state (Zeeman split state), it can be revealed by the use of a magnetic field, and different electronic levels used as different qubit states, and electrons moving between levels using microwave radiation or lasers.

[0005] In an ion trap quantum computer, a surface ion trap is used to control the ions used in quantum computing, and surface electrodes are used to generate an electric field for manipulating and trapping ions floating in free space. The surface electrode potential of the ion trap is successively controlled by a DAC. The surface electrodes generate an electric field that can be used to move ions around.

[0006] Quantum computers use different channels to handle different qubits. These channels can take the form of different resonant frequencies, which can generate magnetically sensitive qubits, such as ions, using different magnetic fields and gradients.

[0007] However, the range of magnetic fields that can be used before the Zeeman state begins to split asymmetrically is limited. Therefore, the total number of channels that can be supported by using different channels is limited. This is not a problem if there is only a limited number of gates, and gates with fixed parameters, since the fixed parameters can be applied to all qubits within a particular channel.

[0008] However, there are some gates that require variable parameters in different parts. An example of a gate with variable parameters is a rotation gate, where the rotation of the qubit is a parameter within the gate. For these gates, a different rotation may be used for each gate. This is problematic because each different parameter requires a different channel. Given the limited number of channels in the device, this limits the number of gates that can be generated simultaneously. As a result, the runtime of such an arrangement becomes considerably longer.

[0009] A rotational gate requires any rotation of the qubit to which it may be applied. For magnetically sensitive qubits, rotation can be applied using an electromagnetic field.

[0010] This invention was born from this background.

[0011] According to the present invention, a device is provided comprising a plurality of independent rotary gates, each independent rotary gate comprising a magnet configured to generate a magnetic field of a predetermined strength at the qubit position of the respective independent rotary gate, wherein the magnetic field is configured to set the resonant frequency of a qubit at the qubit position due to the magnetically sensitive electronic state of the qubit. The device further comprises a first electromagnetic field source configured to generate an electromagnetic field of the resonant frequency over a predetermined period of time across the plurality of independent rotary gates, and each independent rotary gate comprising a controller configured to independently de-resonate a qubit at the respective independent rotary gate at a predetermined time within the predetermined period.

[0012] The applied rotation is around the x-axis or y-axis, and the z-axis is parallel to the magnetic field generated by the magnet. The relative rotation axis between one electromagnetic pulse and another generated by an electromagnetic field source can be changed by adjusting the pulse phase. For example, if the first electromagnetic pulse pulses the first electromagnetic pulse at a first time point and the second electromagnetic pulse pulse is at a second time (multiple) π / 2 later, the first electromagnetic pulse controls the rotation around one of the axes (e.g., the x-axis), and the second electromagnetic pulse controls the rotation around the other axis (e.g., the y-axis).

[0013] De-resonating a qubit may involve moving the qubit so that it is in a different magnetic field, or it may involve changing the magnetic field so that the qubit resonates at a different frequency.

[0014] A single, larger magnetic structure may exist that forms a magnet for each independent rotating gate and generates a magnetic field of a predetermined strength at the qubit position for each independent rotating gate.

[0015] One or each independent rotating gate may further include a magnetic switch configured to adjust the magnetic field at the qubit position, and de-resonating the qubit involves switching the magnetic switch. Thus, over a given period, the magnetic field at the qubit position changes such that the qubit's resonant frequency changes and the qubit becomes no longer sensitive to the electromagnetic field.

[0016] A combination of magnetic fields of predetermined intensity generates a second resonance frequency, and the device further comprises a second electromagnetic field source configured to generate an electromagnetic field of the second resonance frequency. Thus, the qubit may move from the first resonance frequency to the second resonance frequency. Preferably, the difference between the first and second resonance frequencies is such that there is little interference between the two resonance frequencies. In this way, the frequency difference may be at least 1 MHz.

[0017] One or each independent rotating gate may further comprise a plurality of electrodes configured to position the qubit, and de-resonating the qubit includes applying a voltage to the electrodes to move the qubit.

[0018] The magnetic field may include the magnetic field gradient. This means that different lateral positions are exposed to different magnetic fields and therefore have different resonant frequencies. Thus, removing a qubit results in exposing the qubit to different magnetic fields and therefore resonating at different frequencies.

[0019] The magnetic switch may include an electromagnet that allows for easy on and off switching. Additionally, the magnet for generating the magnetic field may include an electromagnet.

[0020] One or all of the magnets in the independent rotating gates may be provided with a magnetic bypass configured to change the magnetic field at the qubit position and move the qubit out of resonance for a predetermined time, and the controller is configured to control the magnetic bypass switch to change the magnetic field at the qubit position.

[0021] The magnet may be equipped with a current-carrying wire, and the magnetic bypass may be equipped with a switch for changing the path of the current through the wire. The switch may be a transistor.

[0022] The specified time may be a single period of the Rabi frequency, thereby allowing the degree of rotation to be applied to the qubit.

[0023] Another aspect of the present invention provides a method for applying rotation to a magnetically sensitive qubit. The method includes generating a magnetic field at the qubit location such that the magnetic field generates a resonant frequency at the qubit location, generating an electromagnetic field at the resonant frequency for a predetermined time over a predetermined period, and de-removing the qubit from resonance for a predetermined time within the predetermined period.

[0024] De-resonating a qubit may involve applying an additional magnetic field to the qubit's location. Additionally, generating a magnetic field at the qubit's location may involve generating a magnetic field gradient. If a magnetic field gradient exists, de-resonating a qubit may involve moving the qubit such that its resonant frequency changes.

[0025] A device is provided that includes a plurality of independent phase rotation gates, each phase rotation gate comprising a magnet configured to generate a magnetic field of a predetermined intensity at the qubit position of each rotation gate, the magnetic field being configured to set the resonance frequency of a qubit at the qubit position due to the magnetically sensitive electronic state of the qubit. Each independent phase rotation gate comprises a controller configured to independently, with each independent phase rotation gate, decouple the qubit from resonance. The phase rotation is about the z-axis.

[0026] The resonance frequency can be set to a "reference clock" and the phase of the qubit can be adjusted by decoupling the qubit from the resonance frequency. For example, increasing the magnetic field increases the angular frequency of the qubit and thus the phase increases (compared to the "reference clock" frequency). Reducing the magnetic field reduces the angular frequency of the qubit and thus the phase reduces (compared to the "reference clock" frequency). Once the desired phase rotation relative to the reference clock frequency is achieved, the qubit is moved back into resonance and thus can resume rotation at the resonance frequency.

[0027] The controller may control the qubit decoupled from resonance for a predetermined period and the qubit may then be returned to resonance.

[0028] One, or each phase rotation gate, may comprise a magnetic switch. The magnetic switch can be used to decouple the qubit from resonance and thus adjust the phase of the qubit. The magnetic switch may comprise an electromagnet.

[0029] One or each phase rotation gate may include a plurality of electrodes configured to position the qubit, and removing the qubit from resonance includes applying a voltage to the electrodes to move the qubit. The magnetic field may include a magnetic field gradient, and thus, moving the qubit changes the magnetic field to which the qubit is subjected. This changes the angular frequency, and thus the phase relative to the "reference clock" frequency.

[0030] The magnet may include a magnetic bypass configured to change the magnetic field at the qubit position to remove the qubit from resonance. The magnet can include a current-carrying wire, and the magnetic bypass can include a switch for changing the path of the current passing through the wire.

[0031] There may be a first qubit for the first phase rotation gate and a second qubit for the second phase rotation gate. Different magnetic fields may be applied to each of the qubits to change their phases. In this way, different phase rotations may be applied to different qubits within a larger-scale processor.

[0032] According to the present invention, a method is provided for applying independent rotations to a plurality of qubits at a plurality of qubit positions, the qubits having magnetically sensitive electronic states. The method includes generating a magnetic field of a predetermined intensity at the qubit position, the magnetic field setting the resonance frequency of the qubit at the qubit position due to the magnetically sensitive electronic state of the qubit, and removing a certain qubit from resonance from the plurality of qubits. The qubit may be removed from resonance for a predetermined period and then returned to resonance.

[0033] De-resonating a qubit may involve applying an additional magnetic field to the qubit's location. Generating a magnetic field of a predetermined intensity at the qubit's location may involve generating a magnetic field gradient. De-resonating a qubit may involve moving the qubit so that its resonant frequency changes.

[0034] The magnetic field may be generated by a magnet with a magnetic bypass, and de-resonating the qubit may involve controlling a magnetic switch to change the magnetic field at the qubit's position.

[0035] The magnet may be equipped with a current-carrying wire, and the magnetic bypass may be equipped with a switch for changing the path of the current through the wire.

[0036] According to the present invention, there exists a device comprising a quantum processor, a first electromagnetic field source configured to generate a first electromagnetic field at a first frequency, and a second electromagnetic field source configured to generate a second electromagnetic field at a second frequency different from the first frequency. The quantum processor includes a switchable magnet having a first position for generating a first magnetic field and a second position for generating a second magnetic field. The quantum processor also includes a magnetic structure configured to generate a magnetic field gradient in space, and due to the magnetically sensitive electronic state of a qubit, when the switchable magnet is in the first position, the magnetic field at the first position sets the resonance frequency of a qubit at the first position to a first frequency, and the magnetic field at the second position sets the resonance frequency of a qubit at the second position to a second frequency. When the switchable magnet is in the second position, the qubit at the first position has a resonance frequency at the second frequency.

[0037] The present invention provides a method for changing the resonance frequency of a qubit having a magnetically sensitive electronic state, the method comprising generating a magnetic field gradient in space, such that, due to the magnetically sensitive electronic state of the qubit, a magnetic field at a first position sets the resonance frequency of a qubit at the first position to a first frequency, and a magnetic field at a second position sets the resonance frequency of a qubit at the second position to a second frequency. The method further comprises generating an additional magnetic field such that the qubit at the first position has a resonance frequency at the second frequency.

[0038] An additional magnetic field is offset so that its magnetic gradient or shape remains the same, but it is magnetically offset.

[0039] The magnetic field gradient may be linear or nonlinear.

[0040] Here, the present invention will be described in more detail, albeit only as an example, with reference to the attached drawings. [Brief explanation of the drawing]

[0041] [Figure 1] This shows the arrangement of channels generated by gates within a quantum computer. [Figure 2] This demonstrates quantum gates. [Figure 3] The arrangement of multiple gates according to the present invention is shown. [Figure 4] An alternative quantum gate configuration is shown. [Figure 5] The magnetic field generating means according to the present invention is shown. [Figure 6a] This demonstrates an alternative quantum gate. [Figure 6b] This demonstrates an alternative quantum gate.

[0042] Figure 1 shows the arrangement of channels 1, 2, 3, and 4 in the quantum computer. A magnetic field gradient is applied, and the channels are formed at intervals of approximately 1 mT and approximately 10 μm.

[0043] Using ytterbium ions as qubits, there is an ultrafine splitting between a 12.64 GHz 2S1 / 2 F=0 manifold and an F=1 manifold in the absence of a magnetic field. In addition, the frequencies of the F=1, mF=+ / -1 state increase / decrease linearly with the magnetic field due to the Zeeman effect. Various combinations of these states have been proposed to fabricate qubits.

[0044] Each different magnetic field has a different energy level division, which can then be addressed using electromagnetic fields of different frequencies. For example, a qubit on channel 1 can be addressed using an electromagnetic field 15 MHz higher than the division frequency, and a qubit on channel 2 can be addressed using an electromagnetic field 30 MHz higher than the division frequency. Thus, channels are addressed using different electromagnetic frequencies.

[0045] The device has multiple multi-channel regions, each region having the same magnetic field gradient and arrangement of channels. Therefore, when an electromagnetic field 30 MHz higher than the frequency division is applied to the device, it is applied to all qubits in channel 2. If there is a rotation gate whose rotation can be any value between 0 and 2π, then, depending on the duration of the electromagnetic field, the same rotation will be applied to any qubit in channel 2 of any gate on the device, provided that the magnetic field and qubit positions remain the same.

[0046] Figure 2 shows the magnetic field structures (e.g., generated using energized wires) 10, 11 and the location of the qubit 15 within the magnetic field. In this embodiment, the magnetic field is 2 mT, setting a resonant frequency 30 MHz above the division frequency. A magnetic switch 20, including an electromagnet on the energized wire, is positioned nearby.

[0047] There is an electromagnetic field source 26 configured to generate an electromagnetic field that is 15 MHz higher than the division frequency. Similarly, electromagnetic field sources 27, 28, and 29 are configured to generate magnetic fields that are 30 MHz, 45 MHz, and 60 MHz higher than the division frequency, respectively.

[0048] The electromagnetic field source 27 generates an electromagnetic field with a duration of 2π in the Rabi frequency at a frequency of 30MHz, which is above the division frequency (+30MHz) applied to channel 2. If the entire 2π electromagnetic field is applied to the qubit 15, a rotation of 2π can be generated. However, at time π / 2 (in the Rabi frequency), the controller 41 switches the magnetic switch. This is achieved by applying current to the magnetic switch 20. The magnetic switch increases the magnetic field at the qubit position, thereby changing the resonance of the qubit. At point π / 2 (in the Rabi frequency), the qubit no longer resonates with the +30MHz wave, and therefore the rotation can stop. Thus, a rotation of π / 2 is applied, and no further rotations are applied. Different rotations can be applied in this way. For example, if a rotation of 4π / 3 is required, the magnetic switch can be switched on at 4π / 3.

[0049] The magnetic field applied by the magnetic switch is sufficient to move the qubit away from the resonant frequency. Alternatively, a magnetic field of 1 mT can be applied, which is sufficient to bring the qubit into the next channel. If the electromagnetic field source 28 (at +45 MHz) is generating an electromagnetic field, the qubit may rotate according to the duration of the electromagnetic field source 28. For example, there may be additional rotations.

[0050] Figure 3 illustrates multiple gates on a device with multiple qubits, each in the same channel, i.e., having the same resonant frequency. As can be seen, there is a controller 41 for each gate. The global electromagnetic field is generated for 2π at the resonant frequency (e.g., +30MHz higher than the division frequency). The controller 41 for each gate can switch each magnetic switch at different times so that each qubit has a different rotation. For example, one qubit may have π / 3 rotations, another π / 2, another 3π / 2, and so on. Thus, a single electromagnetic wave can be transmitted to all qubits in channel 2 (i.e., all qubits resonating at 30MHz), but with different rotations applied to different qubits by using individual switches. This shows a single controller for all qubit positions, but different controllers could be used for each individual qubit position.

[0051] Although this embodiment is described using a magnetic field gradient, the magnetic switch can also be used in conjunction with a static (i.e., no gradient) magnetic field.

[0052] Figure 4 illustrates the arrangement of electrode pairs 31, 32, 33, 34, 35, 36, 37, and 38, each connected to controller 41. A voltage can be applied to the electrodes to move the qubit. For systems with a magnetic field gradient that moves the qubit, the magnetic field to which the qubit is supplied, and therefore the resonant frequency, changes. Therefore, in the channel 2 qubit, applying a voltage to the electrodes for a predetermined time in a +30 MHz electromagnetic field can move the qubit 5 μm in the x-direction. For example, the voltage can be applied for a time of π / 2 of the Rabi frequency in the electromagnetic field. This changes the magnetic field into which the qubit enters, and therefore the resonant frequency. Thus, the qubit is supplied with only π / 2 of the electromagnetic field and therefore undergoes rotation of only π / 2 of the applied Rabi frequency.

[0053] Thus, the applied rotation is equal to the Rabi frequency of the ion multiplied by the duration for which the electromagnetic pulse (at the resonant frequency) is applied.

[0054] Figure 5 illustrates three identical gates on the device, with each gate arrangement similar to that shown in Figure 4, and each gate having its own controller 41. Similar to Figure 3 above, different rotations can be applied to each different qubit position by independently moving each qubit of each gate.

[0055] Figure 6a shows a conventional arrangement of current-carrying wires for generating a magnetic field gradient, used in conjunction with the arrangements in Figures 1-4. However, Figure 6b shows an alternative current-carrying wire with a bypass, which can be used as an alternative method to de-resonate the qubit. The bypass includes a switch to an alternative current path. Changing the current path changes the magnetic field, and therefore the resonance frequency of the qubit changes. At a predetermined time in the electromagnetic field controlled by controller 41, the switch is flipped and the current takes a different path.

[0056] As can be understood, there may be many gates on the device, each having a bypass configuration, as illustrated in Figure 6b.

[0057] The rotation described above is around the x-axis or y-axis, and the z-axis is parallel to the magnetic field generated by the magnet. The relative axis of rotation between one electromagnetic pulse and another generated by an electromagnetic field source can be changed by adjusting the pulse phase.

[0058] The z-axis is defined by the magnetic field, but the x and y axes are relative and are not defined until the first rotation occurs (by the first electromagnetic pulse). All subsequent rotations are then relative to this. For example, if the second electromagnetic pulse has a phase of π / 2 with respect to the first electromagnetic pulse (based on the resonance frequency), then the second rotation will be around the y-axis. For example, for a single-frequency pulse of form A(t)*sin(w*t+Φ) where w is the resonance (or angular) frequency, t is time, Φ is the pulse phase, and the axis of rotation is given by cos Φ*x+sin Φ*y.

[0059] The magnetic field generated by the magnet sets the resonant reference frequency for the qubit. Therefore, a change in the magnetic field supplied to the qubit changes the angular rotation of the qubit. Thus, the rate of angular rotation can increase or decrease relative to the reference frequency. This results in a phase shift relative to the reference frequency. For example, an increase in the magnetic field leads to an increase in angular frequency and an increase in phase relative to the reference frequency. A decrease in the magnetic field leads to a decrease in angular frequency and a decrease in phase relative to the clock frequency.

[0060] The qubit can be de-resonated for a predetermined period of time that generates a phase shift relative to the reference frequency. As described, all methods and apparatus for de-resonating the qubit illustrated in Figures 2, 3, 4, 5, and 6b can be used to de-resonate the qubit for a predetermined period of time. As will be understood by those skilled in the art, electromagnetic field sources 26, 27, 28, and 29 are not required for the phase rotation.

[0061] A qubit can be de-resonated for a predetermined period and become a second resonant frequency. The phase difference is generated by the difference in rotation between the two resonant frequencies over the predetermined period. Therefore, a specific phase difference can be induced.

[0062] As shown in Figure 2, the resonance frequency at the qubit position is set by the magnetic field structures 10 and 11, and the controller 41 controls the magnetic switch. The magnetic switch increases the magnetic field at the qubit position so that the angular rotation increases and therefore the phase of the qubit increases with respect to the reference frequency. To achieve the desired rotation with respect to the reference frequency, the qubit is de-resonated for only a predetermined time.

[0063] Although the magnetic switch 20 is described as increasing the magnetic field, it can equally decrease both the magnetic field strength and the qubit position.

[0064] Figure 3 illustrates a plurality of gates, each having a controller and a magnetic switch, so that the phase rotation of each qubit can be controlled.

[0065] Figures 4 and 5 illustrate an arrangement in which each gate includes multiple electrodes. In this embodiment, the magnetic field structure generates a magnetic field gradient, and different voltages applied to the electrodes move the qubit so that the magnetic field gradient, which the qubit is provided as a change, changes. For a predetermined time, the qubit is out of resonance to generate a predetermined phase difference with respect to the clock at the original resonant frequency, and then returns to resonance to resume angular rotation at the angular (or resonant) frequency.

[0066] Figure 6b shows a magnetic bypass that can be used to induce a phase difference by changing the magnetic field at the qubit for a predetermined period of time, thereby de-resonating the qubit.

[0067] The methods for de-resonating the qubits, as illustrated in Figures 2, 3, 4, 5, and 6b, can be used independently or in alternative combinations. For example, both the magnetic field and the qubit position can be changed.

[0068] While the present invention describes the use of separate magnets for each gate, an alternative is a single magnetic structure spanning multiple gates that generates a predetermined magnetic field at the qubit positions of all gates.

[0069] While this invention describes the use of a controller for each gate, those skilled in the art will understand that all gates can be controlled independently using a single controller.

[0070] The values ​​given here are illustrative, but different spacings between channels may be used, both physically and magnetically.

[0071] Figure 1 shows a magnetic field gradient with multiple channels. As explained, an additional magnetic field may be applied to the entire region. This would have the effect of increasing or decreasing the magnetic field over the entire region, although the overall shape or gradient of the magnetic field would remain the same. There is an offset from the magnetic field illustrated in Figure 1. If the applied additional magnetic field is 1 mT, the qubit that was originally in channel 1 will be in channel 2 (because the total magnetic field supplied to the qubit is 2 mT). Similarly, the previous qubit in channel 2 will be in channel 3. In this way, it is possible to move qubits between channels without moving the qubits in space.

[0072] The straight-line distance between different channels may be at least 500 nm, and there may be a frequency difference of at least 1 MHz.

[0073] An additional offset magnetic field can be applied using the magnetic switch shown in Figure 2. Alternatively, a magnetic bypass (independent of the magnetic structure used to generate the magnetic field gradient) may be used. In a bypass or switch, there is a first global magnetic field, or offset, at the first position, and the qubit may be in the first channel. The first global magnetic field, or offset, may be zero, or it may not be zero. However, in a bypass or switch, there is a second global magnetic field, or offset, at the second position, and the qubit may be in the second channel (without moving in space) due to the change in the global magnetic field, or the offset. This method can be used to move a qubit between adjacent channels or between non-adjacent channels.

[0074] The magnetic field gradient shown in Figure 1 is linear. However, it does not have to be linear, and it may be quadrilateral or square in shape.

[0075] Although the present invention has been described in combination with a single qubit gate, it can be equally well applied to two or more qubit gates.

[0076] Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in consideration of this disclosure.

[0077] As used herein, “and / or” should be taken as a specific disclosure of each of two specific features or components that have or do not have the other. For example, “A and / or B” should be taken as a specific disclosure of (i) A, (ii) B, and (iii) A and B, as each of them would be described separately herein.

[0078] Unless otherwise indicated by the context, the above-described descriptions and definitions of features are not limited to any particular aspect or embodiment of the present invention, but apply equally to all aspects and embodiments described herein.

[0079] Those skilled in the art will understand the present invention better by referring to several embodiments, which have been described as examples. Not limited to the disclosed embodiments, alternative embodiments may be constructed without departing from the scope of the invention as defined in the appended claims.

Claims

1. A device comprising multiple independently controllable rotary gates, wherein one of the multiple independently controllable rotary gates is A magnetic structure configured to generate a magnetic field at a qubit location, wherein the magnetic field is configured to set the resonance frequency of a qubit at the qubit location, at least partially based on the magnetically sensitive electronic state of the qubit; A device comprising a controller configured to shift the aforementioned qubit so that it is out of resonance for a certain period of time.

2. The device according to claim 1, wherein a second rotating gate among a plurality of independently controllable rotating gates is configured to shift a second qubit out of resonance for a second fixed period, the second fixed period being independent of the previous fixed period.

3. The device according to claim 1, wherein a shift that causes the qubit to deviate from resonance is configured to cause the qubit to rotate.

4. The device according to claim 1, further comprising an electromagnetic field source configured to generate an electromagnetic field of the resonant frequency in the rotating gate.

5. The device according to claim 4, further comprising a second electromagnetic field source configured to generate an electromagnetic field of a second resonant frequency.

6. The device according to claim 5, wherein the frequency difference between the magnetic field and the second electromagnetic field is at least 1 MHz.

7. The device according to claim 1, wherein the rotating gate further comprises a magnetic switch that is controlled by the controller and configured to adjust the magnetic field at the qubit position.

8. The device according to claim 7, wherein the magnetic switch is configured to shift the qubit out of resonance when activated.

9. The device according to claim 7, wherein the magnetic switch includes an electromagnet.

10. The device according to claim 1, wherein the rotating gate further comprises a plurality of electrodes configured to change the position of the qubit, and the controller is configured to apply voltage to the electrodes to change the position of the qubit.

11. The device according to claim 1, wherein the magnetic field includes a magnetic field gradient.

12. The device according to claim 11, wherein the magnetic field gradient is linear or nonlinear.

13. The device according to claim 1, wherein the magnetic structure includes an electromagnet.

14. The device according to claim 1, wherein the magnetic structure includes a magnetic bypass configured to change the magnetic field at the qubit position and shift the qubit out of resonance, and the controller is configured to control the magnetic bypass to change the magnetic field at the qubit position.

15. The device according to claim 14, wherein the magnetic structure comprises a current-carrying wire, and the magnetic bypass comprises a switch for changing the path of the current through the current-carrying wire.

16. The device according to claim 1, wherein the magnetic structure comprises an energizing wire.

17. The device according to claim 16, wherein the magnetic structure comprises a switch, the switch is configured to change the path of the current through the wire.

18. The device according to claim 1, wherein the aforementioned certain period is at least partially based on the Rabi frequency.

19. A method for applying a rotary gate, wherein the method is a) Placing qubits having magnetically sensitive electronic states at qubit locations, b) Generating a magnetic field at the qubit location such that the magnetic field sets a resonant frequency at the qubit location, at least in part, based on the magnetically sensitive electronic state of the qubit. c) Shifting the qubit out of resonance for a certain period of time at the qubit position, and applying rotation to the qubit, Methods that include...

20. The method according to claim 19, further comprising: positioning a second qubit at a second qubit position; and shifting the second qubit at the second qubit position so that it is out of resonance for a second fixed period, wherein the second fixed period is independent of the aforementioned fixed period.

21. The method according to claim 19, further comprising generating an electromagnetic field at the qubit position.

22. The method according to claim 21, wherein the electromagnetic field comprises the resonance frequency.

23. The method according to claim 19, wherein the aforementioned period is at least partially based on the Rabi frequency.

24. The method according to claim 19, wherein shifting the qubit at the qubit position includes physically moving the qubit by applying a plurality of voltages to a plurality of electrodes at the qubit position.

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