Automatic quantum searching of object databases

Patent metadata

Field	Value
Publication number	US-11874838-B2
Application number	US-202117561368-A
Country	US
Kind code	B2
Filing date	Dec 23, 2021
Priority date	Dec 10, 2018
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A method includes measuring an amplitude of a state of a quantum circuit, the amplitude corresponding to a first location in an object database. In the embodiment, the method includes executing, using a classical processor and a first memory, a verification operation, responsive to measuring the amplitude, to verify a target object in the first location. In the embodiment, the method includes re-measuring a second amplitude of a second state of the quantum circuit, the second amplitude having undergone a first plurality of amplitude amplifications, the second amplitude corresponding to a second location in the object database, the second location being verified as the target object, and wherein a total number of the first plurality of amplitude amplifications being less than a square root of a set of objects in the object database.

First claim

What is claimed is:

1. A method comprising:
performing a measurement process on a state of a quantum circuit, the measurement process resulting in an amplitude corresponding to the state of the quantum circuit and further corresponding to a first location in an object database;
executing, using a quantum processor and a second memory, a search operation comprising a first quantum amplification operation, a result of the first quantum amplification operation on the amplitude removing a target object basis state from the uniform superposition representation of the state of the quantum circuit;
executing, using a classical processor and a first memory, a verification operation, the verification operation comparing a target object with a first object, the first object stored in the first location; and
executing, using the quantum processor and the second memory, responsive to the verification operation determining that the target object is different from the first object, a second quantum amplification operation, wherein a sum of the first quantum amplification operation and the second quantum amplification operation is less than a threshold value determined from a set of objects in the object database.

2. The method of claim 1 , wherein a result of the second quantum amplification operation comprises a second amplitude corresponding to a second location in the object database, further comprising:
executing, using the classical processor and the first memory, a second verification operation comparing the target object with a second object, the second object stored in the second location.

3. The method of claim 2 , wherein the second quantum amplification operation is a member of a second plurality of quantum amplification operations, further comprising:
incrementing, responsive to the second verification operation determining that the target object is different from the second object, the second plurality of quantum amplification operations; and
repeating, until a stop criterion is satisfied, a third search operation and a third verification operation, the third search operation comprising the incremented second plurality of quantum amplification operations.

4. The method of claim 3 , wherein the stop criterion comprises the earlier of a determination that the third verification operation is successful and a number of quantum amplification operations reaching a square root of a number of objects in the object database.

5. The method of claim 1 , further comprising:
generating, prior to executing the search operation, a set of amplitudes, an amplitude in the set of amplitudes corresponding to a location in the object database.

6. The method of claim 1 , wherein the second quantum amplification operation comprises an incrementing of the first quantum amplification operation.

7. The method of claim 1 , wherein the search operation is performed using an inverted quantum circuit, the inverted quantum circuit generated from a quantum circuit using at least one two-qubit controlled not gate (CNOT gate) and at least one one-qubit rotation gate, the quantum circuit generated from a quantum algorithm.

8. A computer usable program product comprising a computer-readable storage device, and program instructions stored on the storage device, the stored program instructions comprising:
program instructions to perform a measurement process on a state of a quantum circuit, the measurement process resulting in an amplitude corresponding to the state of the quantum circuit and further corresponding to a first location in an object database;
program instructions to execute, using a quantum processor and a second memory, a search operation comprising a first quantum amplification operation, a result of the first quantum amplification operation on the amplitude removing a target object basis state from the uniform superposition representation of the state of the quantum circuit;
program instructions to execute, using a classical processor and a first memory, a verification operation, the verification operation comparing a target object with a first object, the first object stored in the first location; and
program instructions execute, using the quantum processor and the second memory, responsive to the verification operation determining that the target object is different from the first object, a second quantum amplification operation, wherein a sum of the first quantum amplification operation and the second quantum amplification operation is less than a threshold value determined from a set of objects in the object database.

9. The computer usable program product of claim 8 , wherein the program instructions are stored in a computer readable storage device in a data processing system, and wherein the computer usable code is transferred over a network from a remote data processing system.

10. The computer usable program product of claim 8 , wherein the program instructions are stored in a computer readable storage device in a server data processing system, and wherein the computer usable code is downloaded over a network to a remote data processing system for use in a computer readable storage device associated with the remote data processing system.

11. The computer usable program product of claim 8 , wherein a result of the second quantum amplification operation comprises a second amplitude corresponding to a second location in the object database, the stored program instructions further comprising:
program instructions to execute, using the classical processor and the first memory, a second verification operation comparing the target object with a second object, the second object stored in the second location.

12. The computer usable program product of claim 11 , wherein the second quantum amplification operation is a member of a second plurality of quantum amplification operations, the stored program instructions further comprising:
program instructions to increment, responsive to the second verification operation determining that the target object is different from the second object, the second plurality of quantum amplification operations; and
program instructions to repeat, until a stop criterion is satisfied, a third search operation and a third verification operation, the third search operation comprising the incremented second plurality of quantum amplification operations.

13. The computer usable program product of claim 12 , wherein the stop criterion comprises the earlier of a determination that the third verification operation is successful and a number of quantum amplification operations reaching a square root of a number of objects in the object database.

14. The computer usable program product of claim 8 , the stored program instructions further comprising:
program instructions to generate, prior to executing the search operation, a set of amplitudes, an amplitude in the set of amplitudes corresponding to a location in the object database.

15. The computer usable program product of claim 8 , wherein the second quantum amplification operation comprises an incrementing of the first quantum amplification operation.

16. The computer usable program product of claim 8 , wherein the search operation is performed using an inverted quantum circuit, the inverted quantum circuit generated from a quantum circuit using at least one two-qubit controlled not gate (CNOT gate) and at least one one-qubit rotation gate, the quantum circuit generated from a quantum algorithm.

17. A computer system comprising a quantum processor, a computer-readable memory, and a computer-readable storage device,

Assignees

• IBM

Inventors

• Hu Shaohan
• Harry Putra Rudy Raymond
• Wood Stephen
• Pistoia Marco
• Gambetta Jay M

Classifications

• G06N10/20

  Models of quantum computing, e.g. quantum circuits or universal quantum computers · CPC title

• G06N10/60

  Quantum algorithms, e.g. based on quantum optimisation, quantum Fourier or Hadamard transforms · CPC title

• G06N10/80

  Quantum programming, e.g. interfaces, languages or software-development kits for creating or handling programs capable of running on quantum computers; Platforms for simulating or accessing quantum computers, e.g. cloud-based quantum computing · CPC title

• G06F16/24564 Primary

  Applying rules; Deductive queries · CPC title

• G06F16/24549 Primary

  Run-time optimisation · CPC title