Granted Patent B2

US 12,204,406 · App. 18/510,754 · Granted Jan 21, 2025

Inventor: Nathan Cody Jones (Los Angeles, CA)

Assignee: GOOGLE LLC

G06F11/1048G06F16/9024G06N10/00

Abstract

Claims (24)

1. A method for error detection in a quantum computing system, the method comprising:

obtaining, by a computing system comprising one or more computing devices, a matched graph comprising one or more edges and a plurality of nodes, the plurality of nodes corresponding to a plurality of qubits of a quantum computing system, the one or more edges having a matching label;

obtaining, by the computing system, an error detection signal comprising a first endpoint and a second endpoint, the first endpoint and the second endpoint corresponding to a first qubit and a second qubit of the plurality of qubits;

determining, by the computing system, an alternating path from the first endpoint to the second endpoint, the alternating path comprising at least one edge of the one or more edges; and

detecting, by the computing system, at least one error position in the quantum computing system based at least in part on the alternating path.

2. The method of claim 1 , further comprising correcting, by the computing system, a quantum measurement from the at least error position at the quantum computing system.

3. The method of claim 1 , wherein the plurality of qubits comprises an interlaced grid of qubits, the interlaced grid comprising a plurality of computation qubits interlaced with a plurality of ancillary qubits.

4. The method of claim 1 , wherein the first endpoint and the second endpoint each correspond to an ancillary qubit.

5. The method of claim 1 , wherein each of the one or more edges corresponds to a computation qubit.

6. The method of claim 1 , wherein determining, by the computing system, the alternating path from the first endpoint to the second endpoint comprises:

determining, by the computing system, a tree comprising a plurality of alternating paths from the first endpoint to each of the plurality of nodes; and

selecting the alternating path terminating at the second endpoint from the tree.

7. The method of claim 1 , wherein each of the one or more edges comprises a weight, and wherein the weight is based at least in part on a likelihood of error.

8. The method of claim 1 , wherein the matching label is indicative of one of a matched edge having a matched condition or an unmatched edge having an unmatched condition, and wherein the alternating path alternates matched edges and unmatched edges.

9. The method of any of claim 1 , wherein a cost of the alternating path comprises a sum of unmatched weights of unmatched edges in the alternating path with a sum of matched weights of matched edges in the alternating path subtracted from the sum of unmatched weights.

10. A quantum computing system, comprising:

quantum hardware comprising a plurality of qubits; and

one or more classical processors;

wherein the one or more classical processors are configured to perform operations, the operations comprising:

obtaining a matched graph comprising one or more edges and a plurality of nodes, the plurality of nodes corresponding to the plurality of qubits, the one or more edges having a matching label;

obtaining an error detection signal comprising a first endpoint and a second endpoint, the first endpoint and the second endpoint corresponding to a first qubit and a second qubit of the plurality of qubits;

determining an alternating path from the first endpoint to the second endpoint, the alternating path comprising at least one edge of the one or more edges; and

detecting at least one error position in the quantum hardware based at least in part on the alternating path.

11. The quantum computing system of claim 10 , wherein at least one of the first endpoint or the second endpoint comprises a boundary node.

Assignments (1)

Continuity (3)

References Cited (14)

Cited By (1)

US 12,561,597