Ionq, Inc.

Duke University

Kenneth Wright

Jason Madjdi Amini

Neal Pisenti

Jungsang Kim

Yunseong Nam

Kai Hudek

Jonathan Albert Mizrahi

Kristin Marie Beck

Sarah Margaret Kreikemeier

Ming Li

Nadir Shah

Tan Liu

David G Angeley

Michael Lurie Goldman

Reinhold Blumel

Jwo-Sy Chen

Jeremy Matthew Sage

Hermann Uys

Jason Hieu Van Nguyen

Nikodem Grzesiak

Aspects of the present disclosure relate generally to systems and methods for use in the implementation and/or operation of quantum information processing (QIP) systems, and more particularly, to a double individual-addressing multi-beam Raman system for use in QIP systems. A technique is described in which a first multi-channel modulator (MCM), a first telecentric zoom lens, and a first interleaver that form a first optical path of the Raman system that receives a first array of beams and adjusts the first array of beams to individually address atomic-based qubits in a chain from a first direction. Moreover, a second MCM, a second telecentric zoom lens, and a second interleaver form a second optical path of the Raman system that receives a second array of beams and adjusts the second arrays of beams to individually address the atomic-based qubits in the chain from a second direction different from the first direction.

Double individual-addressing multi-beam Raman system

The use of multiple ion chains in a single ion trap for quantum information processing (QIP) systems is described. Each chain can have its own set of laser beams with which to implement and operate quantum gates within that chain, where each chain may therefore correspond to a single quantum computing register or core. Operations can be performed in parallel across all of these chains as they can be treated independently from each other. To implement and operate quantum gates between different chains, neighboring chains are merged into a single, larger chain, in which one can perform quantum gates between any of the ions in the larger chain. The combined chains can then be separated again by another shuttling event as needed. To implement and operate quantum gates between ions which do not occupy neighboring chains, swap gates can be used via a sequence of intervening chains.

Quantum computer based on manipulation of ion chains

A method of performing a quantum gate operation in an ion trap quantum computing system includes identifying one or more error mechanisms that cause a quantum computational error in a quantum gate operation on a first trapped ion of an ion chain comprising a plurality of trapped ions, wherein the quantum gate operation is performed by applying a first Raman laser beam and a second Raman laser beam, computing a first amplitude of the first Raman laser beam, and a second amplitude of the second Raman laser beam such that the effect of the identified one or more error mechanisms is accounted for, and applying the first Raman laser beam having the computed first amplitude and the second Raman laser beam having the computed second amplitude on the first trapped ion to perform the quantum gate operation on the first trapped ion.

Improving quantum gate infidelity in trapped ion quantum computers

Aspects of the present disclosure describe techniques for cooling motional states in an ion trap for quantum computers. In an aspect, a method includes performing Doppler cooling and sideband cooling to sweep motional states associated with a motional mode to a zero motional state; applying a gate interaction on a red sideband; detecting, a population of non-zero motional states of the motional mode that remains after performing the Doppler cooling and the sideband cooling; and removing at least part of the population. In another aspect, a method includes performing a Doppler cooling; applying a gate interaction on a red sideband; detecting whether a population of non-zero motional states of the motional mode remains after performing the Doppler cooling; and redistributing the population of the non-zero motional states by Doppler cooling when a population is detected. A quantum information processing (QIP) system that performs these methods is also described.

Cooling high motional states in ion trap quantum computers

Aspects of the present disclosure describe techniques for using a parabolic Cassegrain-type reflector for ablation. For example, a system for ablation loading of a trap is described that includes a reflector having a hole aligned with a loading aperture of the trap, and an atomic source positioned at a focal point of the reflector, where one or more laser beams are reflected from a reflective front side of the reflector and focused on a surface of the atomic source to produce an atomic plume, and the atomic plume once produced passing through the hole in the reflector and through a loading aperture of the trap for loading the trap. A method for ablation loading of a trap within a chamber in a trapped ion system is also described.

Parabolic Cassegrain-type reflector for ablation loading

Aspects of the present disclosure describe techniques for measuring collision rate with spatial filtering of scattered light. For example, a method for characterizing vacuum in a chamber is described that includes generating, inside the chamber, a potential well having a single, shallow potential region within which an ion is trapped, the shallow potential region having a lowest potential of the potential well, optically monitoring the ion within the potential well, detecting, based on the optically monitoring, a movement of the ion away from the shallow potential region in response to a collision with a background gas, and determining a pressure inside the chamber based on a rate of detected movements of the ion.

Techniques for measuring collision rate with spatial filtering of scattered light

Aspects of the present disclosure describe techniques for mitigating charging on optical windows. For example, a device for mitigating charges inside a chamber of a trapped ion system is described that includes an array of parallel wires formed from a single, conductive plate by cutting elongated gaps through an entire thickness of the conductive plate that separate the wires, an outer portion of the conductive plate to which the wires are attached is configured to position the wires to run parallel to one or more trapped ions in the chamber and to position the wires between a dielectric component of the chamber and the one or more trapped ions. A chamber with such an array of parallel wires and a method of using such an array of parallel wires are also described.

Mitigation of charging on optical windows

Growing community of inventors

Berwyn Heights, MD, United States of America

Kenneth Wright