Phase shifter, quantum logic gate apparatus, optical quantum computing apparatus, and phase shift method

Patent metadata

Field	Value
Publication number	US-10860944-B2
Application number	US-201816234083-A
Country	US
Kind code	B2
Filing date	Dec 27, 2018
Priority date	Jun 27, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A phase shifter, a quantum logic gate apparatus, an optical quantum computing apparatus, and a phase shift method, where the phase shifter includes an optical resonant cavity and a quantum point, where a resonance frequency of the optical resonant cavity is ωc, the quantum point is located in the optical resonant cavity, and a transition frequency of the quantum point is ωx, the quantum point and the optical resonant cavity are coupled to form a coupled system, and a transition energy difference of the coupled system is determined by ωc, ωx, and a coupling strength between the quantum point and the optical resonant cavity (g), and ωx is set.

First claim

What is claimed is:

1. A phase shifter, comprising:
an optical resonant cavity, a resonance frequency of the optical resonant cavity being ω c ; and
a quantum point located in the optical resonant cavity, a transition frequency of the quantum point being ω x , the quantum point and the optical resonant cavity being coupled to form a coupled system, a transition energy difference of the coupled system being determined by the ω c , the ω x , and a coupling strength between the quantum point and the optical resonant cavity (g), and the ω x being set to enable the transition energy difference of the coupled system to be same as energy of at least one photon input into the coupled system.

2. The phase shifter of claim 1 , further comprising an adjustment apparatus coupled to the optical resonant cavity and configured to adjust the ω x .

3. The phase shifter of claim 2 , wherein the adjustment apparatus is a heater, and the heater being configured to adjust the ω x by changing temperature of the quantum point.

4. The phase shifter of 1 , wherein the ω x is set to enable a transition energy difference for transition of the coupled system from a ground state to a first-order dressed state to be same as energy of one photon input into the coupled system.

5. The phase shifter of claim 1 , wherein the ω x is set to enable a transition energy difference for transition of the coupled system from a ground state to a second-order dressed state to be same as energy of two photons input into the coupled system.

6. The phase shifter of claim 1 , wherein a transition energy level of the coupled system comprises two first-order dressed states |1− and |1+ , frequencies of the |1− and the |1+ being respectively

ω
c

+

1
2

⁢
Δ

-

1
2

⁢

Δ
2

+

4
⁢

g
2

⁢

⁢
and
⁢

⁢

ω
c

+

1
2

⁢
Δ

+

1
2

⁢

Δ
2

+

4
⁢

g
2

,

the Δ=ω x −ωc , and transition energy difference of the coupled system being determined by a frequency of the |1− or a frequency of the |1+ .

7. The phase shifter of claim 1 , wherein a transition energy level of the coupled system comprises two second-order dressed states |2− and |2+ , frequency of the |2− and the |2+ being respectively

2
⁢

ω
c

+

1
2

⁢
Δ

-

1
2

⁢

Δ
2

+

8
⁢

g
2

⁢

⁢
and
⁢

⁢
2
⁢

ω
c

+

1
2

⁢
Δ

+

1
2

⁢

Δ
2

+

8
⁢

g
2

,

the Δ=ω x −ω c , and the transition energy difference of the coupled system being determined by a frequency of the |2− or a frequency of the |2+ .

8. A quantum logic gate apparatus, comprising:
a first optical splitter;
a second optical splitter; and
two first phase shifters coupled between the first optical splitter and the second optical splitter using a waveguide, and each first phase shifter comprising:
an optical resonant cavity, a resonance frequency of the optical resonant cavity being ω c ; and
a quantum point located in the optical resonant cavity, a transition frequency of the quantum point being ω x , the quantum point and the optical resonant cavity being coupled to form a coupled system, a transition energy difference of the coupled system being determined by the ω c , the ω x , and a coupling strength between the quantum point and the optical resonant cavity (g), and the ω x being set to enable the transition energy difference of the coupled system to be same as energy of at least one photon input into the coupled system.

9. The quantum logic gate apparatus of claim 8 , wherein a transition frequency of a quantum point in a first phase shifter is set to enable a transition energy difference for transition of a coupled system in the first phase shifter from a ground state to a second-order dressed state to be same as

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhang Wen
• Zhang Chen-Xiong

Classifications

• H10D48/3835

  Semiconductor qubit devices comprising a plurality of quantum mechanically interacting semiconductor quantum dots, e.g. Loss-DiVincenzo spin qubits · CPC title

• H10D62/814

  Quantum box structures · CPC title

• G06N10/20 Primary

  Models of quantum computing, e.g. quantum circuits or universal quantum computers · CPC title

• G02F3/026

  based on laser effects · CPC title

• G02F1/01

  for the control of the intensity, phase, polarisation or colour  (G02F1/29, G02F1/35 take precedence) · CPC title