Processing Signals in a Quantum Computing System

• US 20160267032A1
• Filed: 02/27/2015
• Published: 09/15/2016
• Est. Priority Date: 02/28/2014
• Status: Active Grant

• Current Assignee: Rigetti & Co., Inc.
• Original Assignee: Rigetti & Co., Inc.
• Inventors: RIGETTI, Chad Tyler, THOMPSON, Dane Christoffer
• Granted Patent: US 10,192,168 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 13/36 for access to common bus or bus system
• CPC Class Codes: G06F 13/4068 Electrical coupling
• CPC Class Codes: G06F 15/80 comprising an array of processing units with common control, e.g. single instruction multiple data processors G06F15/82 takes precedence ; for correlation function computation G06F17/15
• CPC Class Codes: G06N 10/00 Quantum computing, i.e. information processing based on quantum-mechanical phenomena
• CPC Class Codes: G06N 20/00 Machine learning

Abstract

In some aspects, a quantum computing system includes a control system and a quantum processor cell. The control system generates quantum processor control information for a group of devices housed in the quantum processor cell, and each device in the group has a distinct operating frequency. In some cases, a waveform generator generates a multiplexed control signal based on the quantum processor control information, and the multiplexed control signal is communicated an input signal processing system. In some cases, the input signal processing system includes an input channel configured to receive the multiplexed control signal, a de-multiplexer configured to separate device control signals from the multiplexed control signal, and output channels configured to communicate the respective device control signals into the quantum processor cell.

Claims

1. A quantum computing method comprising:

generating quantum processor control information for a group of devices housed in a quantum processor cell, each device in the group having a distinct operating frequency;

generating a multiplexed control signal based on the quantum processor control information;

communicating the multiplexed control signal on a physical channel into an input signal processing system;

separating device control signals from the multiplexed control signal by de-multiplexing the multiplexed control signal in the input signal processing system; and

communicating the respective device control signals into the quantum processor cell for the group of devices.

2. The quantum computing method of claim 1, comprising communicating the multiplexed control signal from a first, higher temperature stage to a second, lower temperature stage, wherein the input signal processing system and the quantum processor cell operate in the second temperature stage.

3. The quantum computing method of claim 2, wherein the first temperature stage comprises a room temperature stage, and the second temperature stage comprises a cryogenic temperature stage.

4. The quantum computing method of claim 1, comprising de-multiplexing the multiplexed control signal in a low-noise, cryogenic environment.

5. The quantum computing method of claim 1, comprising shielding the quantum processor cell against microwave and optical frequencies, wherein the shielding is performed by at least one of a metallic, superconducting, or lossy material.

6. The quantum computing method of claim 1, wherein the multiplexed control signal comprises a microwave signal communicated by a microwave transmission line.

7. The quantum computing method of claim 1, wherein the quantum processor control information comprises control sequences for the respective devices in the group, and each device control signal corresponds to one of the control sequences.

21. The quantum computing method of claim 1, wherein the group of devices comprises a first group of devices that each have distinct operating frequencies in a frequency range, and the method comprises:

generating first quantum processor control information for the first group of devices;

generating second, distinct quantum processor control information for a second group of devices housed in a quantum processor cell, the second group each having distinct operating frequencies in the frequency range;

generating a first multiplexed control signal based on the first quantum processor control information;

generating a second, distinct multiplexed control signal based on the second quantum processor control information;

communicating the first multiplexed control signal on a first physical channel into the input signal processing system;

communicating the second multiplexed control signal on a second, distinct physical channel into the input signal processing system;

separating a first set of device control signals from the first multiplexed control signal by de-multiplexing the first multiplexed control signal in the input signal processing system;

separating a second, distinct set of device control signals from the second multiplexed control signal by de-multiplexing the second multiplexed control signal in the input signal processing system;

communicating the first set of device control signals into the quantum processor cell for the first group of devices; and

communicating the second set of device control signals into the quantum processor cell for the second group of devices.

22. The quantum computing method of claim 1, wherein:

the quantum processor cell comprises a multi-dimensional array of qubit devices, the multi-dimensional array comprising sub-arrays associated with separate frequency bands, the qubit devices in each sub-array having a qubit operating frequency within the frequency band associated with the sub-array, and

the group of devices comprises a group of the qubit devices in the multi-dimensional array, and the group of qubit devices includes one qubit device in each of the sub-arrays.

8-20. -20. (canceled)

23. (canceled)

24. A quantum computing system comprising:

a control system comprising;

one or more data processors configured to generate quantum processor control information for a group of qubit devices housed in a quantum processor cell, each device in the group having a distinct operating frequency;

a waveform generator configured to generate a multiplexed control signal from the quantum processor control information;

an input signal processing system comprising;

an input channel configured to receive the multiplexed control signal;

a de-multiplexer configured to separate device control signals from the multiplexed control signal; and

output channels configured to communicate the respective device control signals into the quantum processor cell for the group of devices.

25. The quantum computing system of claim 24, wherein the waveform generator comprises an arbitrary waveform generator configured to convert digital signals to analog signals.

26. The quantum computing system of claim 24, wherein the control system is configured to operate at a first, higher temperature stage, and the input signal processing system and the quantum processor cell are configured to operate at a second, lower temperature stage.

30. The quantum computing system of claim 24, wherein the multiplexed control signal comprises a microwave signal, and the quantum computing system comprises a microwave transmission line configured to communicate the multiplexed control signal.

39. The quantum computing system of claim 24, wherein the group of devices comprises a group of qubit devices, the quantum processor control information comprises qubit control information for the group of qubit devices.

40. The quantum computing system of claim 24, wherein the group of devices comprises a group of coupler devices, the quantum processor control information comprises coupler control information for the group of coupler devices.

41. The quantum computing system of claim 24, wherein the group of devices comprises a group of readout devices, the quantum processor control information comprises readout control information for the group of readout devices.

42. The quantum computing system of claim 24, further comprising the quantum processor cell, wherein:

the quantum processor cell comprises a multi-dimensional array of qubit devices, the multi-dimensional array comprising sub-arrays associated with separate frequency bands, the qubit devices in each sub-array having a qubit operating frequency within the frequency band associated with the sub-array, and

the group of devices comprises a group of the qubit devices in the multi-dimensional array, the group of qubit devices includes one qubit device in each of the sub-arrays.

27-29. -29. (canceled)

31-38. -38. (canceled)

43. (canceled)

44. A quantum computing method comprising:

receiving, at an output signal processing system, qubit readout signals from a group of readout devices housed in a quantum processor cell, each readout device in the group having a distinct readout frequency;

generating a multiplexed readout signal in the output signal processing system by multiplexing the qubit readout signals;

communicating the multiplexed readout signal from the output signal processing system on a physical channel;

receiving the multiplexed readout signal at a control system;

identifying, by operation of the control system, qubit readout data from each readout device, the qubit readout data for each respective readout device identified from the multiplexed readout signal based on the distinct readout frequency of the readout device; and

based on qubit readout data, preparing multiplexed quantum processor control information for the quantum processor cell.

45. The quantum computing method of claim 44, comprising communicating the multiplexed readout signal from a first, lower temperature stage to a second, higher temperature stage, wherein the output signal processing system and the quantum processor cell operate in the first temperature stage, and the control system operates in the second temperature stage.

46. The quantum computing method of claim 45, wherein the first temperature stage comprises a cryogenic temperature stage, and the second temperature stage comprises a room temperature stage.

47. The quantum computing method of claim 44, comprising multiplexing the qubit readout signals in a low-noise, cryogenic environment.

48. The quantum computing method of claim 44, comprising shielding the quantum processor cell against microwave and optical frequencies, wherein the shielding is performed by at least one of a metallic, superconducting, or lossy material.

49. The quantum computing method of claim 44, comprising:

generating an analog multiplexed readout signal in the output signal processing system by multiplexing the qubit readout signals;

communicating the analog multiplexed readout signal from the output signal processing system on a physical channel;

generating a digital multiplexed readout signal by digitizing the analog multiplexed readout signal; and

identifying, by operation of the control system, the qubit readout data from the digitized multiplexed readout signal.

50. The quantum computing method of claim 44, wherein the qubit readout data for each respective device corresponds to the qubit readout signal from the device.

51. The quantum computing method of claim 50, wherein the qubit readout data comprise digital information, and the qubit readout signals comprise analog information.

57. The quantum computing method of claim 44, comprising obtaining the qubit readout signals by operation of the readout devices in the quantum processor cell, each of the readout devices operatively coupled to a respective qubit device in the quantum processor cell.

60. The quantum computing method of claim 44, wherein:

the quantum processor cell houses a group of qubit devices, each qubit device having a respective qubit operating frequency,

each of the readout devices is operably coupled to a single, respective one of the qubit devices, and

the qubit readout signal produced by each readout device indicates a state of the qubit device to which the readout device is operably coupled.

61. The quantum computing method of claim 44, wherein the group of readout devices comprises a first group of readout devices that each have distinct operating frequencies in a frequency range, and the method comprises:

receiving, at the output signal processing system, first qubit readout signals from the first group of readout devices;

receiving, at the output signal processing system, second, distinct qubit readout signals from a second, distinct group of readout devices housed in the quantum processor cell, the second group each having distinct operating frequencies in the frequency range;

generating a first multiplexed readout signal in the output signal processing system by multiplexing the first qubit readout signals;

generating a second, distinct multiplexed readout signal in the output signal processing system by multiplexing the second qubit readout signals;

communicating the first multiplexed readout signal from the output signal processing system on a first physical channel;

communicating the second multiplexed readout signal from the output signal processing system on a second, distinct physical channel;

receiving the first and second multiplexed readout signals at the control system;

identifying, by operation of the control system, qubit readout data from each readout device in the first and second groups, the qubit readout data for each respective readout device identified from the first and second multiplexed readout signals based on the distinct readout frequency of the readout device; and

based on qubit readout data, preparing the multiplexed quantum processor control information for the quantum processor cell.

52-56. -56. (canceled)

58-59. -59. (canceled)

62. (canceled)

63. A quantum computing system comprising:

an output signal processing system comprising;

input channels configured to receive qubit readout signals from a group of readout devices housed in a quantum processor cell, each readout device in the group having a distinct readout frequency;

a multiplexer configured to generate a multiplexed readout signal by multiplexing the qubit readout signals; and

an output channel configured to communicate the multiplexed readout signal from the output signal processing system; and

a control system comprising one or more data processors operable to;

receive the multiplexed readout signal;

identify, from the multiplexed readout signal, qubit readout data for each qubit device in the group based on the distinct readout frequency of the readout device; and

based on the qubit readout data, preparing multiplexed quantum processor control information for the quantum processor cell.

64. The quantum computing system of claim 63, wherein the control system is configured to operate at a first, higher temperature stage, and the output signal processing system and the quantum processor cell are configured to operate at a second, lower temperature stage.

65. The quantum computing system of claim 64, wherein the first temperature stage comprises a room temperature stage, and the second temperature stage comprises a cryogenic temperature stage.

75. The quantum computing system of claim 63, comprising:

the quantum processor cell; and

a group of qubit devices housed in the quantum processor cell, each qubit device having a respective qubit operating frequency,

wherein each of the readout devices is operably coupled to a single, respective one of the qubit devices, and the qubit readout signal produced by each readout device indicates a state of the qubit device to which the readout device is operably coupled.

76. The quantum computing system of claim 63, further comprising the quantum processor cell, wherein:

the quantum processor cell comprises a multi-dimensional array of qubit devices, the multi-dimensional array comprising sub-arrays associated with separate frequency bands, the qubit devices in each sub-array having a qubit operating frequency within the frequency band associated with the sub-array, and

wherein the qubit readout signals are associated with a group of the qubit devices in the multi-dimensional array, and the group of qubit devices includes one qubit device in each of the sub-arrays.

77. The quantum computing system of claim 63, wherein the output signal processing system comprises filters, circulators and quantum amplifiers configured to process the qubit readout signals.

66-74. -74. (canceled)