Polarization insensitive state preparation of high nuclear spin ionic qubits

Patent metadata

Field	Value
Publication number	US-12362076-B2
Application number	US-202218050186-A
Country	US
Kind code	B2
Filing date	Oct 27, 2022
Priority date	Dec 9, 2021
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

Embodiments relate to initializing and/or performing state preparation for an atomic object. The controller controls first manipulation sources to provide first manipulation signals and second manipulation sources to provide second manipulation signals. The first and second manipulation signals are incident on the atomic object. The atomic object has a nuclear spin greater than one half. A ground state manifold of the atomic object comprises one or more selected ground manifold states and non-selected ground manifold states. The first manipulation signals are configured to drive transitions from the non-selected ground manifold states to one or more pumped manifolds of the atomic object and suppress transitions out of the selected ground manifold states. The second manipulation signals are configured to stimulate the atomic object to decay a pumped manifold into a decayed state, wherein there is a non-zero probability that the decayed state is one of the selected ground manifold states.

First claim

That which is claimed:

1. A method for initializing an atomic object confined by an atomic object confinement apparatus, the method comprising:
controlling, by a controller associated with the atomic object confinement apparatus, a first manipulation source to provide a first manipulation signal to a particular region of the atomic object confinement apparatus, wherein the atomic object has a nuclear spin greater than one half, a ground state manifold of the atomic object comprises one or more selected ground manifold states and one or more non-selected ground manifold states, and the first manipulation signal is configured to drive transitions from at least one of the one or more non-selected ground manifold states to one or more pumped manifolds of the atomic object and suppress transitions out of the selected ground manifold states; and
controlling, by the controller, a second manipulation source to provide a second manipulation signal to the particular region of the atomic object confinement apparatus to stimulate the atomic object to decay from at least one of the one or more pumped manifolds into a decayed state within the ground manifold, wherein there is a non-zero probability that the decayed state is one of the selected ground manifold states,
wherein the atomic object to be initialized is located in the particular region of the atomic object confinement apparatus.

2. The method of claim 1 , wherein a polarization of the first manipulation signal is configure to suppress transitions from the one or more selected ground manifold states to the one or more pumped manifolds.

3. The method of claim 1 , wherein a propagation direction of the first manipulation signal is perpendicular to a magnetic field direction in the particular region of the atomic object confinement apparatus.

4. The method of claim 1 , wherein the first manipulation signals comprise intra-manifold signals and inter-manifold signals.

5. The method of claim 4 , wherein the atomic object is a singly ionized barium atom and the intra-manifold signals are characterized by a frequency substantially equal to 8 GHz and the inter-manifold signals are characterized by a wavelength substantially equal to 1762 nm.

6. The method of claim 1 , wherein the one or more selected ground manifold states at least partially define a set of qubit states of the atomic object.

7. The method of claim 1 , wherein the method is performed at least one of (a) prior to the execution of a quantum program by a quantum computer controlled by the controller or (b) to re-initialize an atomic object into a qubit space of the quantum computer during the execution of the quantum program by the quantum computer.

8. The method of claim 1 , wherein the atomic object is a singly ionized barium atom and the second manipulation signals are characterized by at least one of (a) a wavelength substantially equal to 614 nm or (b) a wavelength substantially equal to 493 nm.

9. An apparatus comprising at least one processor and memory storing computer-executable instructions, the computer-executable instructions configured to, when executed by the at least one processor, cause the apparatus to at least:
control a first manipulation source to provide a first manipulation signal to a particular region of an atomic object confinement apparatus, wherein the atomic object has a nuclear spin greater than one half, a ground state manifold of the atomic object comprises one or more selected ground manifold states and one or more non-selected ground manifold states, and the first manipulation signal is configured to drive transitions from at least one of the one or more non-selected ground manifold states to one or more pumped manifolds of the atomic object and suppress transitions out of the selected ground manifold states; and
control a second manipulation source to provide a second manipulation signal to the particular region of the atomic object confinement apparatus to stimulate the atomic object to decay from at least one of the one or more pumped manifolds into a decayed state within the ground manifold, wherein there is a non-zero probability that the decayed state is one of the selected ground manifold states,
wherein the atomic object to be initialized is located in the particular region of the atomic object confinement apparatus.

10. The apparatus of claim 9 , wherein the apparatus is a controller of a quantum computer comprising the atomic object confinement apparatus, the first manipulation source, and the second manipulation source.

11. The apparatus of claim 9 , wherein a polarization of the first manipulation signal is configure to suppress transitions from the one or more selected ground manifold states to the one or more pumped manifolds.

12. The apparatus of claim 9 , wherein a propagation direction of the first manipulation signal is perpendicular to a magnetic field direction in the particular region of the atomic object confinement apparatus.

13. The apparatus of claim 9 , wherein the first manipulation signals comprise intra-manifold signals and inter-manifold signals.

14. The apparatus of claim 13 , wherein the atomic object is a singly ionized barium atom and the intra-manifold signals are characterized by a frequency substantially equal to 8 GHz and the inter-manifold signals are characterized by a wavelength substantially equal to 1762 nm.

15. The apparatus of claim 9 , wherein the one or more selected ground manifold states at least partially define a set of qubit states of the atomic object.

16. The apparatus of claim 9 , wherein the first and second manipulation signals are applied to the atomic object at least one of (a) prior to the execution of a quantum program by a quantum computer controlled by the controller or (b) to re-initialize an atomic object into a qubit space of the quantum computer during the execution of the quantum program by the quantum computer.

17. The apparatus of claim 9 , wherein the atomic object is a singly ionized barium atom and the second manipulation signals are characterized by at least one of (a) a wavelength substantially equal to 614 nm or (b) a wavelength substantially equal to 493 nm.

18. A system comprising:
an atomic object confinement apparatus configured to confine an atomic object in a particular region of the atomic object confinement apparatus;
one or more first manipulation sources controllable by a controller of the system and configured to provide first manipulation signals to the particular region of the atomic object confinement apparatus;
one or more second manipulation sources controllable by the controller of the system and configured to provide second manipulation signals to the particular region of the atomic object confinement apparatus; and
the controller comprising at least one processor and memory storing computer-executable instructions, the computer-executable instructions configured to, when executed by the at least one processor, cause the controller to at least:
control a first manipulation source to provide a first manipulation signal to a particular region of an atomic object confinement apparatus, wherein the atomic object has a nuclear spin greater than one half, a ground state manifold of the atomic object comprises one or more selected ground manifold states and one or more non-selected ground manifold states, and the first manipulation signal is configured to drive transitions from at least one of the one or more non-selected ground manifold states to one or more pumped manifolds of the atomic object and suppress transitions out of the selected ground

Assignees

• Quantinuum Llc

Inventors

• Ransford Anthony
• Gaebler John
• An Fangzhao
• Hostetter James
• Schaffer Andrew
• Sletten Lucas Reid

Classifications

• G21K1/20 Primary

  for confining charged particles or handling confined charged particles, e.g. ion traps · CPC title

• G06N10/40 Primary

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

• G06N10/70

  Quantum error correction, detection or prevention, e.g. surface codes or magic state distillation · CPC title

• G06N10/60

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

• G06N10/20

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