Superconducting logic compatible phase shifter

Patent metadata

Field	Value
Publication number	US-2017201224-A1
Application number	US-201514883237-A
Country	US
Kind code	A1
Filing date	Oct 14, 2015
Priority date	Oct 14, 2015
Publication date	Jul 13, 2017
Grant date	—

Abstract

A phase shifter, including two superconducting circuits, is provided. Each of the superconducting circuits includes at least one capacitor coupled in parallel to at least a Josephson junction and at least one inductor, where a respective inductance of each of the Josephson junctions (e.g., a first Josephson junction and a second Josephson junction) is a function of at least a current flow through each of the respective inductors. An effect of any or both of: (1) at least the inductance of the at least the first Josephson junction and (2) at least the inductance of the at least the second Josephson junction causes a phase change of a radio frequency signal received at a first terminal of the phase shifter to generate a phase-shifted radio frequency signal at a second terminal of the phase shifter.

First claim

What is claimed:

1 . A phase shifter comprising:
a first superconducting circuit comprising:
at least a first capacitor coupled in parallel to at least a first Josephson junction and at least a first inductor coupled in parallel to the at least the first Josephson junction, wherein an inductance of the at least the first Josephson junction is a function of at least an amount of a first current flow through the at least the first inductor; and
a second superconducting circuit comprising:
at least a second capacitor coupled in parallel to at least a second Josephson junction and at least a second inductor coupled in parallel to the at least the second Josephson junction, wherein an inductance of the at least the second Josephson junction is a function of at least an amount of a second current flow through the at least the second inductor, and wherein at least an effect of any or both of: (1) at least the inductance of the at least the first Josephson junction and (2) at least the inductance of the at least the second Josephson junction causes a phase change of a radio frequency signal received at a first terminal of the phase shifter to generate a phase-shifted radio frequency signal at a second terminal of the phase shifter.

2 . The phase shifter of claim 1 , wherein the first superconducting circuit comprises a first capacitively-shunted RF-SQUID circuit.

3 . The phase shifter of claim 2 , wherein the second superconducting circuit comprises a second capacitively-shunted RF-SQUID circuit.

4 . The phase shifter of claim 3 , wherein a first resonant frequency of the first capacitively-shunted RF-SQUID circuit is configured based at least on the amount of the first current flow.

5 . The phase shifter of claim 4 , wherein a second resonant frequency of the second capacitively-shunted RF-SQUID circuit is configured based at least on the amount of the second current flow.

6 . The phase shifter of claim 3 further comprising a 90° hybrid coupler comprising: (1) a third terminal coupled to the first terminal of the phase shifter, (2) a fourth terminal coupled to the second terminal of the phase shifter, (3) a fifth terminal coupled to the first capacitively-shunted RF-SQUID circuit, and (4) a sixth terminal coupled to the second capacitively-shunted RF-SQUID circuit.

7 . The phase shifter of claim 6 , wherein each of a first plurality of parameters corresponding to the first capacitively-shunted RF-SQUID circuit and a second plurality of parameters corresponding to the second capacitively-shunted RF-SQUID circuit is selected such that a maximum frequency of each of the first capacitively-shunted RF-SQUID circuit and the second capacitively-shunted RF-SQUID circuit and a minimum frequency of each of the first capacitively-shunted RF-SQUID circuit and the second capacitively-shunted RF-SQUID circuit substantially overlaps with a bandwidth of the hybrid coupler.

8 . The phase shifter of claim 1 , wherein the phase-shifted radio frequency signal is a microwave control signal for controlling at least one superconducting logic based device.

9 . A superconducting integrated circuit comprising:
a phase shifter, the phase shifter comprising:
a first superconducting circuit comprising:
at least a first capacitor coupled in parallel to at least a first Josephson junction and at least a first inductor coupled in parallel to the at least the first Josephson junction, wherein an inductance of the at least the first Josephson junction is a function of at least a first portion of a phase control current flow through the at least the first inductor, and

a second superconducting circuit comprising:
at least a second capacitor coupled in parallel to at least a second Josephson junction and at least a second inductor coupled in parallel to the at least the second Josephson junction, wherein an inductance of the at least the second Josephson junction is a function of at least a second portion of the phase control current flow through the at least the second inductor, and wherein at least an effect of any or both of: (1) at least the inductance of the at least the first Josephson junction and (2) at least the inductance of the at least the second Josephson junction causes a phase change of a radio frequency signal received at a first terminal of the phase shifter to generate a phase-shifted radio frequency signal at a second terminal of the phase shifter; and

a mixer for receiving the phase-shifted radio frequency signal at a first terminal of the mixer and an amplitude control current at a second terminal of the mixer and for providing a modulated radio frequency signal at a third terminal of the mixer.

10 . The superconducting integrated circuit of claim 9 , wherein the first superconducting circuit comprises a first capacitively-shunted RF-SQUID circuit and wherein the second superconducting circuit comprises a second capacitively-shunted RF-SQUID circuit.

11 . The superconducting integrated circuit of claim 10 , wherein a first resonant frequency of the first capacitively-shunted RF-SQUID circuit is configured based at least on the amount of the first portion of the phase control current flow and wherein a second resonant frequency of the second capacitively-shunted RF-SQUID circuit is configured based at least on the amount of the second portion of the phase control current flow.

12 . The superconducting integrated circuit of claim 10 further comprising a 90° hybrid coupler comprising: (1) a third terminal coupled to the first terminal of the phase shifter, (2) a fourth terminal coupled to the second terminal of the phase shifter, (3) a fifth terminal coupled to the first capacitively-shunted RF-SQUID circuit, and (4) a sixth terminal coupled to the second capacitively-shunted RF-SQUID circuit.

13 . The superconducting integrated circuit of claim 10 , wherein each of a first plurality of parameters corresponding to the first capacitively-shunted RF-SQUID circuit and a second plurality of parameters corresponding to the second capacitively-shunted RF-SQUID circuit, is selected such that a maximum frequency of each of the first capacitively-shunted RF-SQUID circuit and the second capacitively-shunted RF-SQUID circuit and a minimum frequency of each of the first capacitively-shunted RF-SQUID circuit and the second capacitively-shunted RF-SQUID circuit substantially overlaps a bandwidth of the 90° hybrid coupler.

14 . The superconducting integrated circuit of claim 9 , wherein the modulated radio frequency signal is a microwave control signal for controlling at least one superconducting logic based device.

15 . The superconducting integrated circuit of claim 9 further coupled to a digital to analog converter for: (1) receiving a digital control signal, (2) converting the digital control signal into the phase control current, and (3) providing the phase control current to the phase shifter.

16 . The superconducting integrated circuit of claim 9 , wherein the modulated radio frequency signal is a qubit control signal for controlling at least one state of at least one qubit.

17 . A phase shifter comprising:
a 90° hybrid coupler comprising a first terminal, a second terminal, a third terminal, and a fourth terminal; a first variable reactance circuit, coupled to the first terminal of the hybrid coupler, comprising:
at least a first capacitor coupled in parallel to at least a first Josephson junction, at least a first inductor coupled in parallel to at least the first Josephson junction, wherein the at least the first inductor is magnetically coupled to at least a second ind

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Strong Joshua A
• Naaman Ofer
• Egan Jonathan D

Classifications

• H01L39/025

  Electricity · mapped topic

• H03H7/20 Primary

  Two-port phase shifters providing an adjustable phase shift · CPC title

• H01P5/12

  Coupling devices having more than two ports (H01P5/04 takes precedence) · CPC title

• H01P1/18

  Phase-shifters (H01P1/165 takes precedence) · CPC title

• H03H7/185

  comprising distributed impedance elements together with lumped impedance elements · CPC title