JP6765656B2 - Quantum gate device - Google Patents

Description

The present invention relates to quantum computing technology.

In recent years, it has been studied to perform quantum information processing by using an artificial atomic structure composed of a superconducting circuit as a qubit. So far, Non-Patent Document 1 has proposed a quantum gate device between a superconducting qubit and a propagating microwave photon.

Non-Patent Document 1 discloses a method of performing SWAP gate between microwave photons and superconducting qubits by constructing a lambda type three-level system.

Koshino, K., Inomata, K., Yamamoto, T., & Nakamura, Y. "Implementation of an Impedance-Matched Λ System by Dressed-State Engineering", Physical Review Letters, 111, 153601, (2013).

In the method of Non-Patent Document 1, only SWAP gate between microwave photon and superconducting qubit is possible, and quantum calculation other than SWAP gate is not possible between microwave photon and superconducting qubit.

The present invention has been made in view of such problems, and an object of the present invention is to provide a quantum gate device capable of performing quantum calculations other than SWAP gates between microwave photons and superconducting qubits. Is.

量子ゲートに対応する係数ξ ₁₁ (ω),ξ ₁₂ (ω),ξ ₂₁ (ω),ξ ₂₂ (ω)を所与として、式(12)-(15)を満たす、マイクロ波ドライブ光の周波数ω _d 、マイクロ波ドライブ光の強度Ω _d 、共振器の周波数 ^- ω _r 、超伝導量子ビットの周波数 ^- ω _a 及び超伝導量子ビットと共振器の結合強度gの少なくとも１つの値を決定する決定部を更に含み、操作部は、決定された値となるように、マイクロ波ドライブ光の周波数ω _d 、マイクロ波ドライブ光の強度Ω _d 、共振器の周波数 ^- ω _r 、超伝導量子ビットの周波数 ^- ω _a 及び超伝導量子ビットと共振器の結合強度gの少なくとも１つを制御する。
The quantum gate device according to one aspect of the present invention has a superconducting quantum bit coupled to a resonator, a first waveguide coupled to a resonator and in which microwave photons are incident, and a superconducting quantum bit. The second waveguide on which the microwave drive light is incident and the frequency of the microwave drive light, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting quantum bit and the superconducting quantum bit It is equipped with an operation unit that can control at least one of the coupling strengths of the resonator, and corresponds to the desired quantum gate, the frequency of the microwave drive light, the intensity of the microwave drive light, and the frequency of the resonator. Further includes a determination unit for determining at least one value of the frequency of the superconducting quantum bit and the coupling strength between the superconducting quantum bit and the resonator, and the operation unit is of the microwave drive light so as to have the determined value. It controls at least one of the frequency, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting quantum bit, and the coupling strength of the superconducting quantum bit and the resonator .
The quantum gate device according to one aspect of the present invention has a superconducting qubit coupled to a resonator, a first waveguide coupled to a resonator and in which microwave photons are incident, and a superconducting qubit. Combined, the second waveguide on which the microwave drive light is incident, the frequency of the microwave drive light, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting qubit and the superconducting qubit and at least one controllable operation of the coupling strength of the resonator comprises a, the frequency of the microwave drive light is omega _d, the intensity of the microwave drive light is omega _d, the frequency of the resonator ^- and omega _r, the frequency of superconducting qubits ^- and ω _a, χ = g ² / a ^{_{(- - ω r - ω a}} ), ω r = - ω r + χ, ω a = - and ω _a -χ , The coupling strength between the superconducting qubit and the resonator is g, and the two clothing states with low energy levels in the clothing state composed of the superconducting qubit and the resonator affected by the microwave drive light are defined. | ~ 1>, | ~ 2>, ω is the frequency of the microwave photon, ω = ω _l , ω _h , (ω _l , ω _h ) = (~ ω ₃₂ , ~ ω ₃₁ ) or (~ ω) _42, and _{~ ω 41), ~ ω 32} = ~ ω 3 - and _{~ ω 2, ~ ω 31 =} ~ ω 3 - and _{~ ω 1, ~ ω 42 =} ~ ω 4 - and ~ ω _2, ~ ω ₄₁ = ~ omega ₄ - and ~ omega _1, and _{Δω = ω h -ω l, ~} ω 1, ~ ω 2, ~ ω 3, is ~ omega ₄ (6) - as defined by (7 '), Assuming that the quantum gate performs the conversion of equations (10) and (11), the frequencies ξ ₁₁ (ω), ξ ₁₂ (ω), ξ ₂₁ (ω), ξ ₂₂ (ω) corresponding to the qubit gate are given by equation (12). )-(15), κ is a predetermined constant, θ _t = θ _l + θ _h, and θ _l , θ _h are defined by equations (5'), (5''). ,

Given the frequencies ξ ₁₁ (ω), ξ ₁₂ (ω), ξ ₂₁ (ω), ξ ₂₂ (ω) corresponding to the quantum gate , the microwave drive light satisfying equations (12)-(15). Determine at least one value of frequency ω _d , microwave drive light intensity Ω _d , resonator frequency ^- ω _r , superconducting quantum bit frequency ^- ω _a and superconducting quantum bit-resonator coupling strength g. determining portion further includes an operation unit, as a determined value, the frequency omega _d of the microwave drive light intensity omega _d of the microwave drive light, the resonator frequency ^- omega _r, superconducting qubits It controls at least one of the frequency ^- ω _a and the coupling strength g between the superconducting quantum bit and the resonator.

Quantum calculations other than SWAP gates can be performed.

A block diagram for explaining an example of a quantum gate device.

[Embodiment]
Hereinafter, the quantum gate device according to the embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the quantum gate device includes a first waveguide 1, a second waveguide 2, a resonator 3, a superconducting qubit 4, an operation unit 5, an input unit 6, a circulator 7, an output unit 8, and a determination. A unit 9 is provided, for example. The operation unit 5 includes, for example, a first operation unit 51, a second operation unit 52, a third operation unit 53, and a fourth operation unit 54.

The superconducting qubit 4 has a two-level system and is coupled to the resonator 3 (see, for example, Reference 1). In many cases, the superconducting qubit 4 actually has a higher level, but in such a case, the lowest two levels are used.

[Reference 1] K. Koshino, K. Inomata, Z. R. Lin, Y. Tokunaga, T. Yamamoto, Y. Nakamura, "Tunable quantum gate between a superconducting atom and a propagating microwave photon", (2016)

The resonator 3 and the superconducting qubit 4 are coupled to the first waveguide 1 and the second waveguide 2, respectively.

The first operation unit 51 can emit microwave drive light. Further, the first operation unit 51 can control the frequency and intensity of the emitted microwave drive light. The first operation unit 51 controls the frequency and intensity of the microwave drive light so that the values are determined by the determination unit 9, for example. For controlling the frequency and intensity of microwave drive light, see, for example, Reference 2.

[Reference 2] K. Inomata, ZR Lin, K. Koshino, WD Oliver, JS Tsai, T. Yamamoto and Y. Nakamura, "Single microwave-photon detector using an artificial Λ-type three-level system", Nature Communications 7 (2016) 12303

The microwave drive light emitted by the first operation unit 51 is incident on the second waveguide 2. The action of the quantum gate between the superconducting qubit 4 and the microwave photon changes depending on the frequency and intensity of the microwave drive light incident on the second waveguide 2. In other words, the microwave drive light affects the clothing state of the superconducting qubit 4 and the resonator 3.

The microwave photon emitted from the input unit 6 is incident on the first waveguide 1 via the circulator 7. The microwave photon incident on the first waveguide 1 interacts with the superconducting qubit 4 according to the above-mentioned clothing state, and returns to the first waveguide 1. The microwave photon returned to the first waveguide 1 is output to the output unit 8 via the circulator 7.

The second operation unit 52, the third operation unit 53, and the fourth operation unit 54 can control the frequency of the resonator 3, the frequency of the superconducting qubit 4, and the coupling strength between the superconducting qubit 4 and the resonator 3, respectively. is there. The second operation unit 52, the third operation unit 53, and the fourth operation unit 54 have, for example, the frequency of the resonator 3, the frequency of the superconducting qubit 4, and the superconducting unit 54 so as to have values determined by the determination unit 9. The coupling strength between the conduction qubit 4 and the resonator 3 is controlled. The frequency of the superconducting qubit 4 is more accurately the frequency between the two levels of the superconducting qubit 4.

The second operation unit 52, the third operation unit 53, and the fourth operation unit 54 are, for example, the strength of the DC current connected to the resonator 3 and the superconducting qubit 4, and the resonator 3 and the superconducting qubit 4. By controlling the strength of the external magnetic field applied to the connected superconducting qubit (SQUID), the frequency of the resonator 3, the frequency of the superconducting qubit 4, and the superconducting qubit 4 and the resonator, respectively. The bond strength of 3 can be controlled.

For details on controlling the frequency of the resonator 3 by the second operation unit 52, refer to, for example, Reference 3.

[Reference 3] Martin Sandberg, CM Wilson, Fredrik Persson, Thilo Bauch, Goran Johansson, Vitaly Shumeiko, Tim Duty, Per Delsing, "Tuning the field in a microwave resonator faster than the photon lifetime", Appl. Phys. Lett. 92, 203501 (2008)

For details on controlling the frequency of the superconducting qubit 4 by the third operation unit 53, refer to, for example, Reference 4.

[Reference 4] R. Barends, J. Kelly, A. Megrant, D. Sank, E. Jeffrey, Y. Chen, Y. Yin, B. Chiaro, J. Mutus, C. Neill, P. O'Malley , P. Roushan, J. Wenner, TC White, AN Cleland, John M. Martinis, "Coherent Josephson qubit suitable for scalable quantum integrated circuits", Pysical Review Letters 111, 080502 (2013)

For details of controlling the coupling strength between the superconducting qubit 4 and the resonator 3 by the fourth operation unit 54, refer to Reference 5, for example.

[Reference 5] Yu Chen, C. Neill, P. Roushan, N. Leung, M. Fang, R. Barends, J. Kelly, B. Campbell, Z. Chen, B. Chiaro, A. Dunsworth, E. Jeffrey, A. Megrant, JY Mutus, PJJ O'Malley, CM Quintana, D. Sank, A. Vainsencher, J. Wenner, TC White, Michael R. Geller, AN Cleland, John M. Martinis, "Qubit Architecture with High" Coherence and Fast Tunable Coupling ", Pysical Review Letters 113, 220502 (2014)

As will be described later, the determination unit 9 gives Eq. (12) given the frequencies ξ ₁₁ (ω), ξ ₁₂ (ω), ξ ₂₁ (ω), ξ ₂₂ (ω) corresponding to the desired quantum gate. -The frequency of the microwave drive light that satisfies (15) is ω _d , the intensity of the microwave drive light Ω _d , the frequency ω _r of the resonator 3, the frequency ω _a of the superconducting quantum bit 4, and the superconducting quantum bit 4. At least one value of the coupling strength g of the resonator 3 is determined.

At this time, the determination unit 9 sets the frequency of the microwave drive light to ω _d , the intensity of the microwave drive light Ω _d , the frequency ω _r of the resonator 3, the frequency ω _a of the superconducting quantum bit 4, and the superconducting quantum bit 4. And a part of the coupling strength g of the resonator 3 is further given, the frequency ω _{d of} the microwave drive light, the intensity Ω _d of the microwave drive light, the frequency ω _r of the resonator 3, and the frequency of the superconducting quantum bit 4. Other parts of ω _a and the coupling strength g of the superconducting quantum bit 4 and the resonator 3 may be determined.

[Technical background]
The Hamiltonian _Har of the system consisting of the superconducting qubit 4 and the resonator 3 becomes as shown in Eq. (1) in the rotating coordinate system according to the amplitude Ω _d and the frequency ω _d of the microwave drive light.

Where χ = g ² / (ω _r -ω _a ) is the variance shift. ω _r is the frequency of the resonator 3, ω _a is the frequency of the superconducting qubit 4, and is the bond strength g between the superconducting qubit 4 and the resonator 3. Here, it is assumed that ω _r , ω _a , and g are predetermined fixed values. a is the annihilation operator of the superconducting qubit 4, σ is the annihilation operator of the resonator 3, and † means the transposed conjugate.

The four energy levels from the bottom of the system consisting of the superconducting qubit 4 and the resonator 3 are | g, 0>, | e, 0>, | g, 1>, | e, 1>. This is the eigenstate when the drive field is off, in other words, when there is no microwave drive light. If ω _d is defined as ω _a -2χ <ω _d <ω _a , then in the rotating coordinate system of ω _d , the energy level structure is ω _{| g, 0>} <ω _{| e, 0>} <ω _{| e, 1 >} <Ω _{| g, 1>} is a nested type.

On the other hand, when the drive field is on, in other words, when there is microwave drive light, these states are in the clothes state, and can be written as equations (2)-(5).

Here, θ _l and θ _h are defined by Eqs. (5'), (5'').

Then, the intrinsic energies ~ ω ₁ , ~ ω ₂ , ~ ω ₃ , ~ ω ₄ of the above-mentioned clothes state are given by equations (6)-(7').

In this 4-level system, energy relaxation is performed from | ~ 3>, | ~ 4> to | ~ 1>, | ~ 2>, and photons are then emitted to the first waveguide 1. The relaxation rate of the clothing state, which consists of the resonator 3 and the superconducting qubit 4, ^~ κ ₃₁ , ^~ κ ₃₂ , ^~ κ ₄₁ , ^~ κ ₄₂ is given by Eqs. (8) and (9). With i = 3,4, j = 1,2, ^~ κ _ij means the relaxation rate from | ~ i> to | ~ j>. θ _t = θ _l + θ _h . κ is the relaxation rate of the resonator 3 itself and is a predetermined constant.

The propagating microwave photon and this clothed system perform transformations as shown in equations (10) and (11). ω is the frequency of microwave photons, and ω = ω _l , ω _h . Δω = ω _h -ω _l . The definitions of ω _l and ω _h will be described later.

This corresponds to a quantum gate. | ~ 1>, | ~ 2> are the two-state system of the superconducting qubit 4, in other words, the energy level in the clothing state composed of the superconducting qubit 4 and the resonator 3 influenced by the microwave drive light. Corresponding to two low-ranked clothing states, the base of microwave photons is | ω _l >, | ω _h >, and (ω _l , ω _h ) = (~ ω ₃₂ , ~ ω ₃₁ ) or (~ ω ₄₂ , ~ ω ₄₁ ). Here, for _{example, ~ ω 32 = ~ ω 3} - a _{~ ω 2, ~ ω 31 =} ~ ω 3 - a _{~ ω 1, ~ ω 42 =} ~ ω 4 - a ~ ω _2, ~ ω ₄₁ = ~ ω ₄ - is ~ ω _1.

Here, focusing on the case where the relaxation rate is ~ κ ₃₁ = ~ κ ₃₂ (that is, when θ _t = π / 4, the conditions of ω _d and ω _d are equation (17)). (12)-(15) is ξ ₁₁ (ω _l ) = ξ ₂₁ (ω _l ) = 1, ξ ₁₂ (ω _l ) when (ω _l , ω _h ) = (~ ω ₃₂ , ~ ω ₃₁ ) = ξ ₂₂ (ω _l ) = 0, ξ ₁₁ (ω _h ) = ξ ₂₁ (ω _h ) = 0, ξ ₁₂ (ω _h ) = ξ ₂₂ (ω _h ) = 1. This is also the case when the relaxation rate is ~ κ ₄₁ = ~ κ ₄₂ and when (ω _l , ω _h ) = (~ ω ₄₂ , ~ ω ₄₁ ). That is, the conversion formula for microwave photons and atoms is a SWAP gate as shown in equation (16).

In addition, in order to fix the frequency basis of input / output photons, Δω = ω _h -ω _l = equation (18) must be a constant.

A omega _d and Omega _d when subsequent When constant SWAP gates [Delta] [omega omega _d ^sw and Omega _d ^sw is the formula (19) and (20).

At this time, the frequency basis of the microwave photon is given by Eqs. (21) and (22).

Hereinafter, this frequency basis will be used. Next, the √SWAP gate will be described.

√ To construct the SWAP gate, the decision unit 9 determines ξ ₁₁ (ω _l ) = 1, ξ ₁₂ (ω _l ) = 0, ξ ₂₁ (ω _l ) = (1 + i) / 2, ξ ₂₂ ( ω _l ) = (1-i) / 2,ξ ₁₁ (ω _h ) = (1-i) / 2,ξ ₁₂ (ω _h ) = (1 + i) / 2,ξ ₂₁ (ω _h ) = 0 , ξ ₂₂ (ω _h ) = 1 or ξ ₁₁ (ω _l ) = 1, ξ ₁₂ (ω _l ) = 0, ξ ₂₁ (ω _l ) = (1-i) / 2, ξ ₂₂ (ω _l ) = (1 + i) / 2,ξ ₁₁ (ω _h ) = (1 + i) / 2,ξ ₁₂ (ω _h ) = (1-i) / 2,ξ ₂₁ (ω _h ) = 0,ξ ₂₂ ( Select ω _d and Ω _d such that ω _h ) = 1. At this time, the value may deviate within the allowable error range. At this time, if the frequency bases of the microwave photons are selected to be in equations (21) and (22), the bases of the SWAP gate and the √SWAP gate are equal.

In the above description, the determination unit 9 fixes ω _r , ω _a , g to predetermined values and corresponds to the desired quantum gate ξ ₁₁ (ω _l ), ξ ₁₂ (ω _l ). Ω _d so that, ξ ₂₁ (ω _l ), ξ ₂₂ (ω _l ), ξ ₁₁ (ω _h ), ξ ₁₂ (ω _h ), ξ ₂₁ (ω _h ), ξ ₂₂ (ω _h ) can be obtained. , Ω _d was decided, but this is just an example.

The determination unit 9 fixes a part of ω _r , ω _a , g, Ω _d , ω _d and corresponds to the desired quantum gate ξ ₁₁ (ω _l ), ξ ₁₂ (ω _l ), ξ ₂₁ ( _{ω l), ξ 22 (ω} l), ξ 11 (ω h), ξ 12 (ω h), ξ 21 (ω h), as ξ ₂₂ (ω _h) is obtained, ω _r, ω _a, Other parts of g, Ω _d , ω _d may be determined. For example, the determination unit 9 fixes Ω _d and ω _d and corresponds to the desired quantum gate ξ ₁₁ (ω _l ), ξ ₁₂ (ω _l ), ξ ₂₁ (ω _l ), ξ ₂₂ (ω _l ). ), Ξ ₁₁ (ω _h ), ξ ₁₂ (ω _h ), ξ ₂₁ (ω _h ), ξ ₂₂ (ω _h ) may be determined so that ω _r , ω _a , g can be obtained.

Incidentally, so far in the description of, because it was a predetermined value a frequency omega _a frequency omega _r and superconducting quantum bit 4 of the resonator 3, the frequency of the frequency omega _r and superconducting quantum bit 4 of the resonator 3 the shift of the omega _a did not mention, when moving the frequency omega _a frequency omega _r and superconducting quantum bit 4 of the resonator 3, it is necessary to consider the shift. In consideration of the shift, in the above description, the frequency of the resonator 3 ^- and omega _r, the frequency of the superconducting qubit 4 ^- and ^{_{ω a, χ = g 2 /}} (- ω r - - ω a ) ^{_{and, ω r = - ω r +}} χ, ω a = - may be used as the ω _a -χ.

The determination unit 9 corresponds to the desired quantum gate, ξ ₁₁ (ω _l ), ξ ₁₂ (ω _l ), ξ ₂₁ (ω _l ), ξ ₂₂ (ω _l ), ξ ₁₁ (ω _h ), ξ ₁₂ ( Determine the values of ω _r , ω _a , g, Ω _d , ω _d corresponding to ω _h ), ξ ₂₁ (ω _h ), ξ ₂₂ (ω _h ) so that the operation unit 5 becomes the determined value. In addition, by controlling ω _r , ω _a , g, Ω _d , and ω _d , it is possible to configure a quantum gate device capable of performing quantum calculations other than the SWAP gate.

In addition, quantum entanglement can be generated by the above-mentioned quantum gate device.

[Modification example]
It goes without saying that the above embodiment is only an example and can be appropriately changed without departing from the spirit of the present invention.

For example, the quantum gate device may not include the circulator 7. In this case, for example, in the quantum gate device, the microwave photon emitted from the input unit 6 is incident on the first waveguide 1, and the microwave photon returned from the resonator 3 to the first waveguide 1 is sent to the output unit 8. An incident switch may be provided instead of the circulator 7.

Further, in the above description, the frequency basis defined by Eqs. (21) and (22) was used as the frequency basis of the microwave photon, but the frequency basis of the microwave photon is defined by Eqs. (21) and (22). It is not limited to the frequency basis to be used. As the frequency basis of the microwave photon, a frequency basis other than the frequency basis defined by Eqs. (21) and (22) may be used.

1 1st waveguide 2 2nd waveguide 3 Resonator 4 Superconducting qubit 5 Operation unit 6 Input unit 7 Circulator 8 Output unit 9 Decision unit

Claims (3)

Superconducting qubits coupled to the resonator,
The first waveguide, which is coupled to the resonator and in which microwave photons are incident,
A second waveguide that is coupled to the above superconducting qubit and in which microwave drive light is incident,
At least one of the frequency of the microwave drive light, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting quantum bit, and the coupling strength between the superconducting quantum bit and the resonator can be controlled. Operation unit and
Only including,
The frequency of the microwave drive light, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting quantum bit, and the frequency of the superconducting quantum bit and the resonator so as to correspond to the desired quantum gate. It further includes a determinant that determines at least one value of bond strength.
The operation unit performs the frequency of the microwave drive light, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting quantum bit, and the superconducting quantum bit so as to obtain the determined values. And control at least one of the coupling strengths of the resonator,
Quantum gate device. In the quantum gate device of claim 1,
The operation unit is a first operation unit capable of controlling the frequency of the microwave drive light and the intensity of the microwave drive light.
Quantum gate device. Superconducting qubits coupled to the resonator,
The first waveguide, which is coupled to the resonator and in which microwave photons are incident,
A second waveguide that is coupled to the above superconducting qubit and in which microwave drive light is incident,
At least one of the frequency of the microwave drive light, the intensity of the microwave drive light, the frequency of the resonator, the frequency of the superconducting quantum bit, and the coupling strength between the superconducting quantum bit and the resonator can be controlled. Operation unit and
Oite quantum gate equipment including,
The frequency of the microwave drive light is omega _d, the intensity of the microwave drive light is Omega _d, the frequency of the resonator ^- and omega _r, the frequency of the superconducting qubits ^- and ω _a, χ = g ² / a ^{_{(- - ω r - ω a}} ), ω r = - ω r + χ, ω a = - and ω _a -χ, the bond strength of the superconducting qubit and the resonator and g, the The two clothing states with low energy levels in the clothing state composed of the superconducting quantum bit and the resonator affected by the microwave drive light are | ~ 1> and | ~ 2>, and ω is the above micro. Let the frequency of the wave photon be ω = ω _l , ω _h , (ω _l , ω _h ) = (~ ω ₃₂ , ~ ω ₃₁ ) or (~ ω ₄₂ , ~ ω ₄₁ ), and ~ ω ₃₂ = ~ ω ₃ - a _{~ ω 2, ~ ω 31 =} ~ ω 3 - and _{~ ω 1, ~ ω 42 =} ~ ω 4 - and _{~ ω 2, ~ ω 41 =} ~ ω 4 - and ~ ω _1, Δω = ω _h and _{-ω l, ~ ω 1, ~} ω 2, ~ ω 3, ~ ω 4 of the formula (6) - (7 ') and is defined by, the quantum gate has the formula (10), conversion of (11) Assuming that the coefficients ξ ₁₁ (ω), ξ ₁₂ (ω), ξ ₂₁ (ω), ξ ₂₂ (ω) corresponding to the above quantum gate are defined by Eqs. (12)-(15), κ Is a predetermined constant, θ _t = θ _l + θ _h, and θ _l and θ _h are defined by equations (5') and (5'').

Given the frequencies ξ ₁₁ (ω), ξ ₁₂ (ω), ξ ₂₁ (ω), ξ ₂₂ (ω) corresponding to the quantum gate, the microwave drive satisfying equations (12)-(15). light frequency omega _d, the microwave drive light intensity omega _d, of the resonator frequency ^- omega _r, said superconducting quantum bit frequency ^- omega _a and the superconducting qubits and coupling strength g of the resonator Further includes a decision unit that determines at least one value
The operation unit has the frequency ω _{d of} the microwave drive light, the intensity Ω _d of the microwave drive light, the frequency ^- ω _{r of} the resonator, and the superconducting quantum bit so as to obtain the determined values. Controls frequency ^- ω _a and at least one of the coupling strength g of the superconducting quantum bit and the cavity .
Quantum gate device.

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