OPERATING A MULTI-DIMENSIONAL ARRAY OF QUBIT DEVICES

• US 20160292586A1
• Filed: 02/27/2015
• Published: 10/06/2016
• 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 9,892,365 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 multi-dimensional array of qubit devices. Coupler devices reside at intervals between neighboring pairs of the qubit devices in the multi-dimensional array. Each coupler device is configured to produce an electromagnetic interaction between one of the neighboring pairs of qubit devices. In some cases, each qubit device has a respective qubit operating frequency that is independent of an offset electromagnetic field experienced by the qubit device, and the coupling strength of the electromagnetic interaction provided by each coupler device varies with an offset electromagnetic field experienced by the coupler device. In some cases, readout devices are each operably coupled to a single, respective qubit device to produce qubit readout signals that indicate the quantum state of the qubit device.

Claims

1. A quantum computing system comprising:

a multi-dimensional array of qubit devices, each qubit device having a respective qubit operating frequency that is independent of an offset electromagnetic field experienced by the qubit device; and

coupler devices residing at intervals between neighboring pairs of the qubit devices in the multi-dimensional array, each coupler device being configured to produce an electromagnetic interaction between the respective neighboring pair of qubit devices, each coupler device configured to vary a coupling strength of the electromagnetic interaction according to an offset electromagnetic field experienced by the coupler device.

2. The quantum computing system of claim 1, comprising readout devices associated with the multi-dimensional array of qubit devices, each readout device operably coupled to a single, respective qubit device and configured to produce a qubit readout signal that indicates a state of the respective qubit device, the qubit readout signal produced in response to a readout control signal delivered to the readout device.

3. The quantum computing system of claim 1, wherein each qubit device has two or more nearest-neighbor qubit devices in the multi-dimensional array, and the qubit operating frequency of each qubit device is distinct from the respective qubit operating frequencies of each nearest-neighbor qubit device.

4. The quantum computing system of claim 1, wherein each of the neighboring pairs of qubit devices comprises a first qubit device having a first qubit operating frequency and a second qubit device having a second, distinct qubit operating frequency.

5. The quantum computing system of claim 1, wherein each coupler device has a respective coupler operating frequency that varies with the offset electromagnetic field experienced by the coupler device, and the coupling strength varies according to the coupler operating frequency.

9. The quantum computing system of claim 1, wherein the multi-dimensional array defines a first set of intervals along a first dimension of the array and a second set of intervals along a second dimension of the array, a first subset of the coupler devices reside at the first set of intervals, and a second subset of the coupler devices reside at the second set of intervals.

10. The quantum computing system of claim 1, wherein the multi-dimensional array comprises a two-dimensional array, and the qubit devices define rows and columns of the two-dimensional array.

14. The quantum computing system of claim 10, wherein the multi-dimensional array comprises a three-dimensional array, and the qubit devices define rows, columns and layers of the three-dimensional array.

21. The quantum computing system of claim 1, comprising an electromagnetic waveguide system, the electromagnetic waveguide system comprising an interior surface that defines an interior volume of intersecting waveguides, wherein the qubit devices are housed in the electromagnetic waveguide system.

6-8. -8. (canceled)

11-13. -13. (canceled)

15-20. -20. (canceled)

22-27. -27. (canceled)

28. A quantum computing method comprising:

receiving qubit control signals in a multi-dimensional array of qubit devices, each qubit device having a respective qubit operating frequency that is independent of an offset electromagnetic field experienced by the qubit device, the qubit control signal received by each qubit device being configured to manipulate a quantum state of the qubit device; and

receiving coupler control signals at coupler devices, the coupler devices residing at intervals between neighboring pairs of the qubit devices in the multi-dimensional array, the coupler control signal received by each coupler device being configured to produce an electromagnetic interaction between the neighboring pair of qubit devices that the coupler device resides between, a coupling strength of the electromagnetic interaction produced by each coupler device being influenced by an offset electromagnetic field experienced by the coupler device.

29. The quantum computing method of claim 28, wherein each qubit control signal comprises a microwave pulse.

30. The quantum computing method of claim 28, wherein each qubit control signal is configured to execute a single-qubit gate on qubit device that receives the qubit control signal.

31. The quantum computing method of claim 28, wherein a component of the coupler control signals comprise DC signals that cause the coupler devices to experience offset electromagnetic fields.

32. The quantum computing method of claim 31, wherein:

each of the coupler devices has a respective coupler operating frequency that varies with the offset electromagnetic field experienced by the coupler device,

the coupling strength varies according to the coupler operating frequency,

each of the neighboring pairs of qubit devices comprises a first qubit device having a first qubit operating frequency and a second qubit device having a second, distinct qubit operating frequency, and

the offset electromagnetic field experienced by each coupler device tunes the coupler device to a frequency range associated with at least one of the first qubit operating frequency or the second qubit operating frequency.

33. The quantum computing method of claim 32, wherein a second component of the coupler control signals comprise AC signals that drive the coupler devices while the coupler operating frequencies are tuned to the respective frequency ranges, and each control device is driven at a drive frequency that corresponds to a sum or difference of the first qubit operating frequency and the second qubit operating frequency.

34. The quantum computing method of claim 28, wherein each coupler control signal is configured to execute a two-qubit gate on the respective pair of qubit devices that the coupler device resides between.

35. The quantum computing method of claim 28, wherein each qubit device has two or more nearest-neighbor qubit devices in the multi-dimensional array, and the qubit operating frequency of each qubit device is distinct from the respective qubit operating frequencies of each nearest-neighbor qubit device.

36. The quantum computing method of claim 28, wherein each of the neighboring pairs of qubit devices comprises a first qubit device having a first qubit operating frequency and a second qubit device having a second, distinct qubit operating frequency.

37-40. -40. (canceled)

41. A quantum computing system comprising:

a multi-dimensional array of qubit devices, each qubit device having a respective qubit operating frequency that is independent of an offset electromagnetic field experienced by the qubit device; and

readout devices associated with the multi-dimensional array of qubit devices, each readout device operably coupled to a single, respective qubit device and configured to produce a qubit readout signal that indicates a state of the respective qubit device.

42. The quantum computing system of claim 41, wherein the qubit devices have respective qubit operating frequencies in a first frequency band, and the readout devices have respective readout frequencies in a second, separate frequency band.

43. The quantum computing system of claim 41, wherein the qubit devices have respective qubit operating frequencies in a frequency band, and the readout devices have respective readout frequencies that are interleaved between the qubit operating frequencies in the frequency band.

44. The quantum computing system of claim 41, wherein each qubit device has two or more nearest-neighbor qubit devices in the multi-dimensional array, and the qubit operating frequency of each qubit device is distinct from the respective qubit operating frequencies of each nearest-neighbor qubit device.

45. The quantum computing system of claim 44, wherein each readout device has a respective readout frequency and two or more nearest-neighbor readout devices, and the readout frequency of each readout device is distinct from the respective readout frequencies of each nearest-neighbor readout device.

46. The quantum computing system of claim 41, comprising coupler devices residing at intervals between neighboring pairs of the qubit devices in the multi-dimensional array, each coupler device being configured to produce an electromagnetic interaction between the respective neighboring pair of qubit devices that the coupler device resides between.

48. The quantum computing system of claim 41, wherein the multi-dimensional array comprises a two-dimensional array, and the qubit devices define rows and columns of the two-dimensional array.

51. The quantum computing system of claim 41, wherein the multi-dimensional array comprises a three-dimensional array, and the qubit devices define rows, columns and layers of the three-dimensional array.

55. The quantum computing system of claim 41, wherein each of the readout devices is capacitively coupled to the single, respective qubit device.

58. The quantum computing system of claim 41, comprising an electromagnetic waveguide system, the electromagnetic waveguide system comprising an interior surface that defines an interior volume of intersecting waveguides, wherein the qubit devices are housed in the electromagnetic waveguide system.

47. (canceled)

49-50. -50. (canceled)

52-54. -54. (canceled)

56-57. -57. (canceled)

59-60. -60. (canceled)

61. A quantum computing method comprising:

receiving qubit control signals in a multi-dimensional array of qubit devices, each qubit device having a respective qubit operating frequency that is independent of an offset electromagnetic field experienced by the qubit device, the qubit control signal received by each qubit device being configured to manipulate a quantum state of the qubit device; and

producing qubit readout signals at readout devices associated with the multi-dimensional array of qubit devices, each readout device operably coupled to a single, respective qubit device, each qubit readout signal produced by one of the readout devices based on an electromagnetic interaction between the readout device and the respective qubit device.

62. The quantum computing method of claim 61, wherein the qubit devices have respective qubit operating frequencies in a first frequency band, and the readout devices have respective readout frequencies in a second, separate frequency band.

63. The quantum computing method of claim 61, wherein the qubit devices have respective qubit operating frequencies in a frequency band, and the readout devices have respective readout frequencies that are interleaved between the qubit operating frequencies in the frequency band.

64. The quantum computing method of claim 61, wherein each qubit device has two or more nearest-neighbor qubit devices in the multi-dimensional array, and the qubit operating frequency of each qubit device is distinct from the respective qubit operating frequencies of each nearest-neighbor qubit device.

65. The quantum computing method of claim 61, wherein each readout device has two or more nearest-neighbor readout devices, and a readout frequency of each readout device is distinct from respective readout frequencies of each nearest-neighbor readout device.

70. The quantum computing method of claim 61, further comprising receiving readout control signals at the readout devices.

71. The quantum computing method of claim 70, wherein each readout control signal is received by a respective readout device, and each qubit readout signal is produced by a respective readout device in response to the readout control signal received by the respective readout device.

72. The quantum computing method of claim 71, wherein the qubit readout signal produced by each readout device is influenced by a quantum state of the qubit device that the readout device is operably coupled to.

66-69. -69. (canceled)

73-107. -107. (canceled)