Calculating device

Patent metadata

Field	Value
Publication number	US-11836458-B2
Application number	US-202017012716-A
Country	US
Kind code	B2
Filing date	Sep 4, 2020
Priority date	Feb 21, 2020
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

According to one embodiment, a calculating device includes nonlinear oscillators, connectors, and a controller. One of the connectors connects at least two of the nonlinear oscillators. The nonlinear oscillators include first and second nonlinear oscillators. The first nonlinear oscillator includes a first circuit part and a first conductive member. The first circuit part includes first and second Josephson junctions. The second nonlinear oscillator includes a second circuit part and a second conductive member. The second circuit part includes third and fourth Josephson junctions. Numbers of the connectors connected to the first and second connectors are first and second numbers, respectively. The second number is greater than the first number. The controller performs at least a first operation of supplying a first signal to the first conductive member and supplying a second signal to the second conductive member. The second signal is different from the first signal.

First claim

What is claimed is:

1. A calculating device, comprising:
a plurality of nonlinear oscillators;
a plurality of connectors, one of the connectors connecting at least two of the nonlinear oscillators; and
a controller,
the nonlinear oscillators including a first nonlinear oscillator and a second nonlinear oscillator,
the first nonlinear oscillator including a first circuit part and a first conductive member,
the first circuit part including a first Josephson junction and a second Josephson junction,
the second nonlinear oscillator including a second circuit part and a second conductive member,
the second circuit part including a third Josephson junction and a fourth Josephson junction,
a number of the connectors connected to the first nonlinear oscillator being a first number,
a number of the connectors connected to the second nonlinear oscillator being a second number,
the second number being greater than the first number,
in a first period, the controller being configured to perform at least a first operation of supplying a first signal to the first conductive member and supplying a second signal to the second conductive member,
the second signal being different from the first signal,
in the first period, the controller setting the first and second signals to cause an absolute value of (p 2 −Δ 2 )/K 2 to be less than an absolute value of (p 1 −Δ 1 )/K 1 ,
p 1 being an amount proportional to an amplitude of an alternating current component of a signal of the first nonlinear oscillator,
Δ 1 being a difference between a resonant frequency of the first nonlinear oscillator and ½ of a frequency of the first signal,
K 1 being an anharmonicity of the first nonlinear oscillator,
p 2 being an amount proportional to an amplitude of an alternating current component of a signal of the second nonlinear oscillator,
Δ 2 being a difference between a resonant frequency of the second nonlinear oscillator and ½ of a frequency of the second signal,
K 2 being an anharmonicity of the second nonlinear oscillator.

2. The device according to claim 1 , wherein
p 1 is a first pump amplitude of the first nonlinear oscillator,
Δ 1 is a first detuning of the first nonlinear oscillator,
K 1 is a first Kerr coefficient of the first nonlinear oscillator,
p 2 is a second pump amplitude of the second nonlinear oscillator,
Δ 2 is a second detuning of the second nonlinear oscillator, and
K 2 is a second Kerr coefficient of the second nonlinear oscillator.

3. The device according to claim 1 , wherein
the nonlinear oscillators includes a third nonlinear oscillator,
the third nonlinear oscillator includes a third circuit part and a third conductive member,
the third circuit part includes a fifth Josephson junction and a sixth Josephson junction,
a number of the connectors connected to the third nonlinear oscillator is a third number,
the third number is greater than the second number,
the first operation includes supplying a third signal to the third conductive member in the first period, and
the third signal is different from the first signal and different from the second signal.

4. The device according to claim 3 , wherein
in the first period, the controller sets the first, second, and third signals to cause an absolute value of (p 2 −Δ 2 )/K 2 to be less than an absolute value of (p 1 −Δ 1 )/K 1 and to cause an absolute value of (p 3 −Δ 3 )/K 3 to be less than the absolute value of (p 2 −Δ 2 )/K 2 ,
p 1 is an amount proportional to an amplitude of an alternating current component of a signal of the first nonlinear oscillator,
Δ 1 is a difference between a resonant frequency of the first nonlinear oscillator and ½ of a frequency of the first signal,
K 1 is an anharmonicity of the first nonlinear oscillator,
p 2 is an amount proportional to an amplitude of an alternating current component of a signal of the second nonlinear oscillator,
Δ 2 is a difference between a resonant frequency of the second nonlinear oscillator and ½ of a frequency of the second signal,
K 2 is an anharmonicity of the second nonlinear oscillator,
p 3 is an amount proportional to an amplitude of an alternating current component of a signal of the third nonlinear oscillator,
Δ 3 is a difference between a resonant frequency of the third nonlinear oscillator and ½ of a frequency of the third signal, and
K 3 is an anharmonicity of the third nonlinear oscillator.

5. The device according to claim 3 , wherein
in the first period, the controller sets the first, second, and third signals to cause an absolute value of (p 2 −Δ 2 )/K 2 to be less than an absolute value of (p 1 −Δ 1 )/K 1 and to cause an absolute value of (p 3 −Δ 3 )/K 3 to be less than the absolute value of (p 2 −Δ 2 )/K 2 ,
p 1 is a first pump amplitude of the first nonlinear oscillator,
Δ 1 is a first detuning of the first nonlinear oscillator,
K 1 is a first Kerr coefficient of the first nonlinear oscillator,
p 2 is a second pump amplitude of the second nonlinear oscillator,
Δ 2 is a second detuning of the second nonlinear oscillator,
K 2 is a second Kerr coefficient of the second nonlinear oscillator,
p 3 is a third pump amplitude of the third nonlinear oscillator,
Δ 3 is a third detuning of the third nonlinear oscillator, and
K 3 is a third Kerr coefficient of the third nonlinear oscillator.

6. A calculating device, comprising:
a plurality of nonlinear oscillators;
a plurality of connectors, one of the connectors connecting at least two of the nonlinear oscillators; and
a controller,
the nonlinear oscillators including a first nonlinear oscillator and a second nonlinear oscillator,
the first nonlinear oscillator including a first circuit part and a first conductive member,
the first circuit part including a first Josephson junction and a second Josephson junction,
the second nonlinear oscillator including a second circuit part and a second conductive member,
the second circuit part including a third Josephson junction and a fourth Josephson junction,
a number of the connectors connected to the first nonlinear oscillator being a first number,
a number of the connectors connected to the second nonlinear oscillator being a second number,
the second number being greater than the first number,
in a first period, the controller being configured to perform at least a first operation of supplying a first signal to the first conductive member and supplying a second signal to the second conductive member,
the second signal being different from the first signal,
in the first period, the controller controlling the first and second signals to cause an absolute value of a first detuning of the first nonlinear oscillator to be less than an absolute value of a second detuning of the second nonlinear oscillator.

7. The device according to claim 6 , wherein
in the first period, the controller controls the first and second signals to cause the first detuning to be a product of the first number and a proportionality coefficient, and to cause the second detuning to be a product of the second number and the proportionality coefficient.

8. The device according to claim 6 , wherein
the first detuning is a difference between a resonant frequency of the first nonlinear oscillator and ½ of a frequency of the first signal, and
the second detuning is a difference between a resonant frequency of the second nonlinear oscillator and ½ of a frequency of the second signal.

9. The device according to claim 6 , wherein
the first detuning is (p/K)γCz 1 ,
the second detuning is (p/K)γCz 2 ,
p is an average pump amplitude of the first and second nonlinear oscillators,
K is an average Kerr coefficient of the first and second nonl

Assignees

• Toshiba Kk

Inventors

• Kanao Taro
• Goto Hayato

Classifications

• G06F7/381 Primary

  using cryogenic components, e.g. Josephson gates · CPC title

• G06N10/00

  Quantum computing, i.e. information processing based on quantum-mechanical phenomena · CPC title

• G06N10/40

  Physical realisations or architectures of quantum processors or components for manipulating qubits, e.g. qubit coupling or qubit control · CPC title