Computational device, quantum state generation device, computation method, quantum state generation method and program

Abstract

To provide an arithmetic device capable of reducing the time required to generate the superposition state to make it relatively short when generating a distinguishable superposition state of multiple quantum states using an oscillator that performs parametric oscillation.SOLUTION: The arithmetic device includes: plan generation means that generates a plan to control the oscillator so that the strength of the pump signal input to the oscillator that performs parametric oscillation is increased from a first value over time, and then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, and then decreases to a fourth value; quantum state generation means that generates a quantum state by controlling the oscillator based on the plan; and calculation means that uses the obtained quantum state to perform calculations.SELECTED DRAWING: Figure 1

Claims

1. A planning generation means for generating a control plan for an oscillator such that the intensity of the pump signal input to the oscillator performing parametric oscillation increases from a first value over time, then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, then decreases to a fourth value. A quantum state generation means that controls the oscillator based on the above plan to generate a quantum state, A computation means that performs calculations using the obtained quantum state, A computing device equipped with the following features.

2. The plan generation means generates a plan in which, after the magnitude of the detuning changes from increasing to decreasing, the intensity of the pump signal changes from increasing to decreasing. The computing device according to claim 1.

3. The plan generation means acquires information indicating the quantum state obtained when the oscillator is controlled based on the generated plan, and updates the plan based on the acquired information. The computing device according to claim 1 or claim 2.

4. The plan generation means updates the plan by using an objective function that represents an evaluation of the quantum state to search for the values ​​of internal parameters included in a first function that represents the intensity of the pump signal over time and the values ​​of internal parameters included in a second function that represents the magnitude of the detuning over time. The computing device according to claim 3.

5. Both the first and fourth values ​​are 0. The first function is a function obtained by multiplying the elapsed time polynomial, where the value at the start of the control over the oscillator for generating the quantum state is 0 and the value at the end of the control over the oscillator for generating the quantum state is 1, by the second value. The second function is a function obtained by multiplying the elapsed time polynomial, where the value at the start of the control over the oscillator for generating the quantum state is 1, and the value at the end of the control over the oscillator for generating the quantum state is 0, by the third value. The computing device according to claim 4.

6. A planning generation means for generating a control plan for an oscillator such that the intensity of the pump signal input to the oscillator performing parametric oscillation increases from a first value over time, then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, then decreases to a fourth value. A quantum state generation means that controls the oscillator based on the above plan to generate a quantum state, A quantum state generation device equipped with the following features.

7. A control plan for the oscillator is generated such that the intensity of the pump signal input to the parametric oscillator increases from a first value over time, then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, then decreases to a fourth value. Based on the above plan, the oscillator is controlled to generate a quantum state. The calculation is performed using the obtained quantum state. A calculation method that includes the following.

8. A control plan for the oscillator is generated such that the intensity of the pump signal input to the parametric oscillator increases from a first value over time, then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, then decreases to a fourth value. Based on the above plan, the oscillator is controlled to generate a quantum state. A method for generating quantum states, including the following.

9. In a computing device that performs calculations using an oscillator that performs parametric oscillation, To generate a control plan for the oscillator such that the intensity of the pump signal input to the oscillator increases from a first value over time, then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, then decreases to a fourth value. Based on the above plan, the oscillator is controlled to generate a quantum state, Performing calculations using the obtained quantum state, A program to execute.

10. A quantum state generation device that generates quantum states by controlling an oscillator that performs parametric oscillation, To generate a control plan for the oscillator such that the intensity of the pump signal input to the oscillator increases from a first value over time, then decreases to a second value, and the magnitude of the detuning between the resonant frequency and the oscillation frequency of the oscillator increases from a third value over time, then decreases to a fourth value. Based on the above plan, the oscillator is controlled to generate a quantum state, A program to execute.

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