Integrating a cryostat that hosts qubits with electronics for controlling the qubits

Patent metadata

Field	Value
Publication number	US-12079690-B2
Application number	US-202117384595-A
Country	US
Kind code	B2
Filing date	Jul 23, 2021
Priority date	Jan 25, 2019
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A quantum computing system includes a cryostat to support a low-temperature vacuum environment during operation of the quantum computing system; a quantum processor positioned in the cryostat; a first electronic control module external to the cryostat; a second electronic control module within the cryostat; at least one optical transmission line connecting the first electronic control module external to the cryostat with the second electronic control module internal to the cryostat, the optical transmission line being configured to transmit optical signals to and from the second electronic control module during operation of the quantum computing system; and a plurality of signal lines connecting the second electronic control module with the quantum processor, a first subset of the signal lines being configured to transmit microwave signals to and from the quantum processor during operation of the quantum computing system.

First claim

What is claimed is:

1. A quantum computing system, comprising:
a cryostat comprising a vacuum chamber, the cryostat being configured to support a low-temperature vacuum environment during operation of the quantum computing system;
a quantum computer processor positioned in the vacuum chamber;
a first electronic control module external to the vacuum chamber;
a second electronic control module within the vacuum chamber;
an optical transmission line connecting the first electronic control module external to the vacuum chamber with the second electronic control module internal to the vacuum chamber, the optical transmission line being configured to transmit optical signals to and from the second electronic control module during operation of the quantum computing system; and
a plurality of signal lines connecting the second electronic control module with the quantum computer processor, a first subset of the signal lines being configured to transmit microwave signals to and from the quantum computer processor during operation of the quantum computing system.

2. A The quantum computing system of claim 1 ,
wherein the second electronic control module comprises one or more digital-to-analog converters configured to receive digital signals and provide analog signals based on the digital signals during operation of the quantum computing system.

3. The quantum computing system of claim 1 , wherein the second electronic control module comprises a de-multiplexing module for receiving a multiplexed optical signal from the optical transmission line and providing de-multiplexed optical signals for producing corresponding microwave signals to the signal lines.

4. The quantum computing system of claim 1 , wherein the vacuum chamber comprises an optical port through which the optical transmission line connects the first electronic control module external to the vacuum chamber with the second electronic control module internal to the vacuum chamber.

5. The quantum computing system of claim 1 , wherein the second electronic control module comprises
a DAC/ADC array to receive digital signals from, and produce digital signals for transmission to, the first electronic control module external to the cryostat,
a mixer array to receive MW signals from, and produce MW signals for transmission to, the quantum computer processor, and
a MW oscillator operatively coupled with
the mixer array to produce the MW signals for transmission to the quantum computer processor, and
the DAC/ADC array to produce the digital signals for transmission to the first electronic control module external to the cryostat.

6. The quantum computing system of claim 1 , wherein the second electronic control module comprises
a DAC/ADC array to
receive digital signals from, and produce digital signals for transmission to, the first electronic control module external to the cryostat, and
receive MW signals from, and produce MW signals for transmission to, the quantum computer processor.

7. The quantum computing system of claim 1 , comprising:
one or more busbars coupled with the inner wall surface of the wall of the vacuum chamber,
wherein the vacuum chamber comprises one or more electrical feedthroughs corresponding to the one or more busbars.

8. The quantum computing system of claim 1 , wherein the quantum computer processor and the second electronic control module are separated within the vacuum chamber by one or more baffles.

9. The quantum computing system of claim 1 wherein the quantum computer processor is a superconducting circuit quantum computer processor.

10. The quantum computing system of claim 1 , wherein the second electronic control module comprises one or more components that produce heat during operation, and the one or more components are thermally coupled to an inner wall surface of a wall of the vacuum chamber.

11. The quantum computing system of claim 10 , wherein an inner wall surface comprises a plurality of planar facets.

12. The quantum computing system of claim 11 , wherein the second electronic control module comprises one or more electronics boards each mounted in thermal contact with a corresponding one of the planar facets.

13. The quantum computing system of claim 1 , further comprising
a cooling system comprising
a wall of the vacuum chamber, the wall having an inner wall surface and an outer wall surface, and
a heat exchanger thermally coupled to the outer wall surface,

wherein components of the second electronic control module are thermally coupled to the inner wall surface, such that the cooling system removes, during operation of the quantum computing system, at least a portion of heat produced by the components of the second electronic control module.

14. The quantum computing system of claim 13 , wherein the cooling system comprises a radiation shield, the radiation shield being disposed in the vacuum chamber and spaced apart from the inner wall surface to encompass the components of the second electronic control module, such that a temperature of the components of the second electronic control module encompassed by the radiation shield is maintained within a target temperature range higher than cryogenic temperatures.

15. The quantum computing system of claim 14 , wherein the target temperature range is 298K to 263K.

16. The quantum computing system of claim 1 , wherein
the vacuum chamber is configured to support, during operation of the quantum computing system, a cryogenic-temperature vacuum environment in a cryogenic-temperature partition of the vacuum chamber, wherein temperatures inside the vacuum chamber are higher outside, than inside, the cryogenic-temperature partition,
the quantum computer processor is positioned in the cryogenic-temperature partition of the vacuum chamber, and
the second electronic control module is positioned within the vacuum chamber and outside the cryogenic-temperature partition thereof, the second electronic control module being arranged in thermal contact with an inner wall of the vacuum chamber.

17. The quantum computing system of claim 16 , wherein the temperature inside the cryogenic-temperature partition is lower than 50K.

18. The quantum computing system of claim 16 , wherein the cryogenic-temperature partition of the vacuum chamber has an operational-temperature sub-partition.

19. The quantum computing system of claim 18 , wherein the temperature inside the operational-temperature sub-partition is lower than 100 mK.

20. The quantum computing system of claim 1 , wherein the optical transmission line is the only transmission line connecting the first electronic control module external to the vacuum chamber with the second electronic control module internal to the vacuum chamber.

21. The quantum computing system of claim 1 , further comprising at least one direct signal line connecting the first electronic control module to the quantum computer processor, the at least one direct signal line bypassing the second control module.

22. The quantum computing system of claim 1 , wherein the transmission line is one of a plurality of transmission lines connecting the first electronic control module external to the chamber with the second electronic control module internal to the chamber.

23. The quantum computing system of claim 22 , wherein the quantum computer processor comprises N total qubits and the plurality of transmission lines includes a total of k transmission lines, where N>>k.

24. A qu

Assignees

• Rigetti & Co Inc

Inventors

• Jones Glenn
• Lion Robert
• Rust Michael
• Turkowski Stefan William
• Taie-Nobarie Nima
• Deshpande Saniya Vilas
• Selvanayagam Michael Karunendra
• Russell Damon Stuart

Classifications

• G06N10/40

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

• G06F1/20 Primary

  Cooling means · CPC title

• G06N10/00 Primary

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