IP Library › Granted Patent US 12,430,580
Granted Patent B2
US 12,430,580 · App. 18/045,672 · Granted Sep 30, 2025

Methods and apparatuses for doppler cooling

Inventor: Michael Lurie Goldman (University Park, MD)
Assignee: IonQ, Inc.
G06N10/40
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Quick Facts
Patent No.
US 12,430,580
App. No.
18/045,672
Granted
Sep 30, 2025
Kind
B2
Abstract

Aspects of the present disclosure may include a method and/or a system for identifying an ion chain having a plurality of trapped ions, selecting at least two non-consecutive trapped ions in the ion chain for implementing a qubit, applying at least a first Raman beam to shuttle at least one neighbor ion of the at least two non-consecutive trapped ions from a ground state to a metastable state, and applying at least a second Raman beam to one or more of the at least two non-consecutive trapped ions, after shuttling the at least one neighbor ion to the metastable state, to transition from a first manifold to a second manifold.

Claims (56)

1. A method of implementing Doppler cooling in a quantum information processing (QIP) system, comprising:

applying a magnetic field to a dual space single species (DSSS) trapped ion to induce frequency differences between a first transition, a second transition, and a third transition between a ground state and an excited state;

applying a first optical beam having a first polarization to the DSSS trapped ion associated with the first transition;

applying a second optical beam having a second polarization to the DSSS trapped ion associated with the second transition; and

applying a third optical beam having a third polarization to the DSSS trapped ion associated with the third transition.

2. The method of claim 1 , wherein:

the first polarization is a σ + polarization;

the second polarization is a π polarization; and

the third polarization is a σ − polarization.

3. The method of claim 1 , wherein:

applying the first optical beam comprises applying the first optical beam on a first red side of the first transition;

applying the second optical beam comprises applying the second optical beam on a second red side of the second transition; and

applying the third optical beam comprises applying the third optical beam on a third red side of the third transition.

4. The method of claim 1 , further comprising applying a repump beam.

5. The method of claim 1 , wherein the magnetic field is between 16 Gauss and 17 Gauss.

6. The method of claim 1 , wherein:

the first optical beam and the third optical beam are the same beam;

applying the first optical beam comprises applying a first optical tone on the same beam; and

applying the third optical beam comprises applying a second optical tone on the same beam.

7. A non-transitory computer readable medium having instructions stored therein that, when executed by one or more processors of a quantum information processing (QIP) system, cause the one or more processors to:

cause a magnet to apply a magnetic field to a dual space single species (DSSS) trapped ion to induce a first transition, a second transition, and a third transition between a ground state and an excited state;

cause a first light source to apply a first optical beam having a first polarization to the DSSS trapped ion associated with the first transition;

cause a second light source to apply a second optical beam having a second polarization to the DSSS trapped ion associated with the second transition; and

cause a third light source to apply a third optical beam having a third polarization to the DSSS trapped ion associated with the third transition.

8. The non-transitory computer readable medium of claim 7 , wherein:

the first polarization is a σ + polarization;

the second polarization is a π polarization; and

the third polarization is a σ − polarization.

9. The non-transitory computer readable medium of claim 7 , wherein:

the instructions for causing the first light source to apply the first optical beam comprises instructions for causing the first light source to apply the first optical beam on a first red side of the first transition;

the instructions for causing the second light source to apply the second optical beam comprises instructions for causing the second light source to apply the second optical beam on a second red side of the second transition; and

the instructions for causing the third light source to apply the third optical beam comprises instructions for causing the third light source to apply the third optical beam on a third red side of the third transition.

10. The non-transitory computer readable medium of claim 7 , further comprising instructions for causing a fourth light source to apply a repump beam.

11. The non-transitory computer readable medium of claim 7 , wherein the magnetic field is between 16 Gauss and 17 Gauss.

12. The non-transitory computer readable medium of claim 7 , wherein:

the first optical beam and the third optical beam are the same beam;

applying the first optical beam comprises applying a first optical tone on the same beam; and

applying the third optical beam comprises applying a second optical tone on the same beam.

13. A quantum information processing (QIP) system, comprising:

a magnetic configured to apply a magnetic field to a dual space single species (DSSS) trapped ion to induce a first transition, a second transition, and a third transition between a ground state and an excited state;

a first light source configured to apply a first optical beam having a first polarization to the DSSS trapped ion associated with the first transition;

a second light source configured to apply a second optical beam having a second polarization to the DSSS trapped ion associated with the second transition;

a third light source configured to apply a third optical beam having a third polarization to the DSSS trapped ion associated with the third transition; and

a controller configured to control one or more of the magnet, the first light source, the second light source, and the third light source.

14. The QIP system of claim 13 , wherein:

the first polarization is a σ + polarization;

the second polarization is a π polarization; and

the third polarization is a σ − polarization.

15. The QIP system of claim 13 , wherein:

the first light source is further configured to apply the first optical beam on a first red side of the first transition;

the second light source is further configured to apply the second optical beam on a second red side of the second transition; and

the third light source is further configured to apply the third optical beam on a third red side of the third transition.

16. The QIP system of claim 13 , further comprising a fourth light source configured to apply a repump beam.

17. The QIP system of claim 13 , wherein the magnetic field is between 16 Gauss and 17 Gauss.

18. The QIP system of claim 13 , wherein:

the first light source and the third light source are the same light source configured to apply a first optical tone on the first optical beam and a second optical tone on the third optical beam.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 12, 2023
From: GOLDMAN, MICHAEL LURIE
To: IONQ, INC.
Reel/Frame 063627/0736 →
Continuity (3)
Continuation In Part 17867414 · Jul 18, 2022
Provisional Application 63222765 · Jul 16, 2021
Related Publication 20230126894A1 · Apr 27, 2023
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