Systems and methods for increasing analog processor connectivity

Patent metadata

Field	Value
Publication number	US-10268622-B2
Application number	US-201715418497-A
Country	US
Kind code	B2
Filing date	Jan 27, 2017
Priority date	Jan 29, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

Topologies for analog computing systems are provided. Qubits in the topology are grouped into cells, and cells are coupled to adjacent cells by inter-cell couplers. At least some cells are coupled to non-adjacent cells via long-range couplers. Long-range couplers may be arranged into coverings so that certain sets of qubits within a covering region may be coupled with a reduced number of couplers. Each cell within a covering region without a long-range coupler may be proximate to a cell with a long range coupler so that each cell within the covering region is no more than a certain coupling distance away from a long-range coupler. Long-range couplers may couple over a greater physical distance than inter-cell couplers. Long-range couplers may couple to qubits over a larger coupling region, and may extend across multiple crossing regions between qubits.

First claim

What is claimed is:

1. A quantum processor comprising:
a plurality of cells, each cell comprising one or more qubits;
one or more inter-cell couplers, each inter-cell coupler providing controllable communicative coupling between a first inter-cell coupling qubit of the one or more qubits to a second inter-cell coupling qubit of another cell, whereby direct coupling by the inter-cell couplers defines an adjacency relationship between the cells of the first and second inter-cell coupling qubit; and
a long-range coupler providing controllable communicative coupling between a first qubit of a first cell and a second qubit of a second cell, the second cell non-adjacent to the first cell;
wherein each inter-cell coupler of the first cell provides direct controllable communicative coupling over a first physical distance which is at most a threshold inter-cell physical coupling distance and the long-range coupler provides direct controllable communicative coupling over a second physical distance at least a threshold long-range physical coupling distance, the long-range physical coupling distance greater than the inter-cell physical coupling distance, and
wherein, fix at least the first cell:
each of the one or more inter-cell couplers couples to the respective first inter-cell coupling qubit at one or more inter-cell coupling region, each inter-cell coupling region having at most an inter-cell coupling area;
the long-range coupler couples to the first qubit over a long-range coupling region having at least a long-range coupling area, the long-range coupling area greater than the inter-cell coupling area;
the long-range coupler passes through one or more intervening cells disposed between the first and second cells; and
the long-range coupler is isolated from the qubits of the intervening cells so that the long-range coupler does not couple the first qubit to any of the intervening qubits.

2. A quantum processor according to claim 1 wherein, for at least the first cell of the one or more cells:
the one or more qubits comprises a plurality of qubits; and
the first cell comprises one or more intra-cell couplers, each intra-cell coupler providing controllable communicative coupling between at least two of the plurality of qubits.

3. A quantum processor according to claim 2 wherein, for at least the first cell: each of the one or more intra-cell couplers couples to the corresponding pair of qubits at one or more intra-cell coupling regions, each intra-cell coupling region having at most an intra-cell coupling area; and the long-range coupler couples to the first qubit over a long-range coupling region, the long-range coupling region which extends across at least a part of each of a plurality of crossing regions of the first qubit.

4. A quantum processor according to claim 3 wherein: each qubit in a first qubit subset of the one or more qubits crosses a portion of each qubit in a second qubit subset of the one or more qubits at a crossing region; each intra-cell coupler provides controllable communicative coupling between a first intra-cell coupling qubit of the first qubit subset and a second intra-cell coupling qubit of the second qubit subset at the corresponding intra-cell coupling region, the intra-cell coupling region proximate to the crossing region; and the first qubit is in the first qubit subset.

5. A quantum processor according to claim 4 wherein: the plurality of intra-cell couplers couple each qubit of the first qubit subset to at least one qubit of the second qubit subset; and the plurality of intra-cell couplers couple each qubit of the second qubit subset to at least one qubit of the first qubit subset.

6. A quantum processor according to claim 4 wherein: the long-range coupling region comprises a first coupling region and a second coupling region, each coupling region coupled to the first qubit; at least one intra-cell coupling region is disposed between the first and second coupling regions; and the long -range coupler passes around the at least one intra-cell coupling region without coupling to the first qubit at the intra-cell coupling region, the long-range coupler communicatively coupling the first and second coupling regions.

7. A quantum processor according to claim 3 wherein the long-range coupler does not extend across the respective crossing region of any one of the plurality of intra-cell couplers.

8. A quantum processor according to claim 3 wherein: the first cell comprises an array of qubits, with the qubits of the first qubit subset extending substantially parallel to a first major axis and the qubits of the second qubit subset extending substantially parallel to a second major axis substantially orthogonal to the first major axis; each of the first and second qubit subsets comprise at least four qubits; the first qubit extends parallel to the major axis of the first qubit for a qubit length distance; and the long-range coupling region extends parallel to the major axis of the first qubit for a coupling length distance which is at least half the qubit length distance.

9. A quantum processor according to claim 7 wherein each of the first and second qubit subsets comprise at least six qubits and the coupling length distance is at least two-thirds the qubit length distance.

10. A quantum processor according to claim 3 wherein the first cell comprises one or more intra-subset couplers, each intra-subset coupler providing controllable communicative coupling between at least two qubits of the first qubit subset which do not share a crossing region.

11. A quantum processor according to claim 10 wherein the one or more intra-subset couplers are disposed proximate to an outer boundary of the first cell.

12. A quantum processor according to claim 1 wherein:
the long-range coupler is one of one or more long-range couplers;
the first and second cells are each one of one or more long-range cells, each of the one or more long-range cells has a respective long-range qubit coupled to at least one of the one or more long-range couplers; and
the plurality of cells comprises one or more local cells, no qubit of the one or more local cells directly coupling to any of the one or more long-range couplers.

13. A quantum processor according to claim 12 wherein the one or more long-range couplers comprise at least two long-range couplers and the at least two long-range couplers couple a plurality of qubits of the first cell to a plurality of qubits of the second cell.

14. A quantum processor according to claim 12 wherein each cell of the one or more local cells has a greater number of intra-cell couplers than each of the long-range cells.

15. A quantum processor according to claim 12 wherein: each pair of the plurality of cells has a corresponding coupling distance based on a number of couplers needed to form a coupling between the pair; each of the one or more local cells is no more than a threshold coupling distance from one of the one or more long-range cells.

16. A quantum processor according to claim 15 wherein: the one or more local cells comprise a first local cell adjacent to the first cell and a second local cell adjacent to the second cell; the first and second local cells have a corresponding inter-cell coupling distance based on a number of inter-cell couplers needed to form a coupling between the first and second local cells without the use of any of the one or more long-range couplers; and the inter-cell coupling distance is greater than the coupling distance corresponding to the first and second local cells, said coupling distance based at least partially on the provision o

Assignees

• D Wave Systems Inc

Inventors

• Hilton Jeremy P
• Roy Aidan Patrick
• Bunyk Paul I
• King Andrew Douglas
• Boothby Kelly T R
• Harris Richard G
• Deng Chunqing

Classifications

• G06N99/002

  Physics · mapped topic

• G06F13/4068 Primary

  Electrical coupling · CPC title

• G06F13/36

  for access to common bus or bus system · CPC title

• G06N10/40

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

• G06N20/00

  Machine learning · CPC title