Christopher A Monroe

US Patent:

20210406757, Dec 30, 2021

Filed:

Jun 29, 2021

Appl. No.:

17/362810

Inventors:

- College Park MD, US
- Durham NC, US
Christopher MONROE - Ellicott City MD, US

International Classification:

G06N 10/00

Abstract:

Aspects of the present disclosure describe techniques that involve an active stabilization of coherent controllers using nearby qubits. In an aspect, a quantum information processing (QIP) system for stabilizing phase damping in qubits is described that provides a first and a second qubit ion, measuring magnetic field fluctuations using the second qubit ion, and generates one or more magnetic fields based on the measured magnetic field fluctuations, the one or more magnetic fields being applied near the first qubit ion to cancel the magnetic field fluctuations to stabilize the phase damping of the first qubit ion. Another such QIP system performs provides a first and a second qubit ion, locks a local oscillator to a frequency reference associated with the second qubit ion, and tracks, using the local oscillator, a frequency of the first qubit ion based on the frequency reference. Methods associated with these QIP systems are also described.

US Patent:

20200219001, Jul 9, 2020

Filed:

Dec 9, 2019

Appl. No.:

16/708025

Inventors:

- College Park MD, US
Yunseong NAM - North Bethesda MD, US
Christopher MONROE - Ellicott City MD, US

International Classification:

G06N 10/00
H03K 19/14
H03K 19/20

Abstract:

The disclosure describes various aspects of a practical implementation of multi-qubit gate architecture. A method is described that includes enabling ions in the ion trap having three energy levels, enabling a low-heating rate motional mode (e.g., zig-zag mode) at a ground state of motion with the ions in the ion trap; and performing a Cirac and Zoller (CZ) protocol using the low-heating rate motional mode as a motional state of the CZ protocol and one of the energy levels as an auxiliary state of the CZ protocol, where performing the CZ protocol includes implementing the multi-qubit gate. The method also includes performing one or more algorithms using the multi-qubit gate, including Grover's algorithm, Shor's factoring algorithm, quantum approximation optimization algorithm (QAOA), error correction algorithms, and quantum and Hamiltonian simulations. A corresponding system that supports the implementation of a multi-qubit gate architecture is also described.

US Patent:

20200201933, Jun 25, 2020

Filed:

Nov 8, 2019

Appl. No.:

16/677922

Inventors:

- Gaithersburg MD, US
Kevin Chengming Qian - Rockville MD, US
Zachary David Eldredge - Washington DC, US
Wenchao Ge - College Station TX, US
Guido Pagano - Washington DC, US
Christopher Roy Monroe - Ellicott City MD, US

International Classification:

G06F 17/17
G06N 10/00
G01N 24/00

Abstract:

A Heisenberg scaler reduces noise in quantum metrology and includes: a stimulus source that provides physical stimuli; a physical system including quantum sensors that receive a first and second physical stimuli; produces a measured action parameter; receives an perturbation pulse; and produces modal amplitude; an estimation machine that: receives the measured action parameter and produces a zeroth-order value from the measured action parameter; a gradient analyzer that: receives the measured action parameter and produces the measured action parameter and a gradient; the sensor interrogation unit that; receives the modal amplitude; receives the gradient and the measured action parameter produces the perturbation pulse; and produces a first-order value from the modal amplitude, the gradient, and the measured action parameter; a Heisenberg determination machine that: receives the zeroth-order value; receives the first-order value; and produces a physical scalar from the zeroth-order value and the first-order value.

US Patent:

20200082291, Mar 12, 2020

Filed:

Jul 17, 2019

Appl. No.:

16/514099

Inventors:

- College Park MD, US
Christopher R. MONROE - Columbia MD, US
Caroline FIGGATT - Denver CO, US

International Classification:

G06N 10/00
G02F 1/11

Abstract:

Aspects of the present disclosure describe techniques for controlling quantum states of ions in an ion chain for a quantum operation. For example, a method is described that includes providing, from a first direction, a global optical beam to the ions in the ion chain, and providing, from a second direction different from the first direction, to each ion in a subset of the ions in the ion chain, a respective addressing optical beam. The method further includes dynamically controlling each of the addressing optical beams being provided by using a respective channel in a multi-channel acousto-optic modulator (AOM) to implement, with the ion chain, one or more quantum gates in a sequence of quantum gates of the quantum operation. Aspects of a quantum information processing (QIP) system that includes the multi-channel AOM for performing the method are also described.