Ionq, Inc.

Duke University

University System of Maryland

Lonq, Inc.

Jason Madjdi Amini

Kai Hudek

Neal Pisenti

Jonathan Albert Mizrahi

Kenneth Wright

Phillip Douglas Solomon

Jwo-Sy Chen

Joel Zvi Apisdorf

Shantanu Debnath

James Michael Williams

Jungsang Kim

Yunseong Nam

Michael Lurie Goldman

Vandiver Chaplin

Jeremy Matthew Sage

Ming Li

Reinhold Blumel

Kristin Marie Beck

Marko Cetina

Sarah Margaret Kreikemeier

Jaime David Wong-Campos

Hermann Uys

Yuan Su

Nikodem Grzesiak

James Walker Steere

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

Aspects of the present disclosure describe devices trapping devices for use in quantum information processing (QIP) architectures, and more particularly, to the use and fabrication of a multi-layer ion trap on shaped glass or dielectric substrate. A method for fabricating the ion trap is described that includes preparing a back surface of the substrate, building a multi-layer stack on the top surface of the substrate, and completing the back etch to break through the substrate and etching through a metal and dielectric in the multi-layer stack to complete the formation of the ion trap. Shaping of the ion trap may also include trap narrowing features, wings, and/or undercutting. An ion trap fabricated using this approach may be used in a QIP system to trap atomic species provided through a hole in the back of the substrate for use as qubits in quantum operations and computations.

Multi-layer ion trap on shaped glass or dielectric substrate

A method of performing a computation using a quantum computer includes modulating motional mode structures of a plurality of trapped ions, each of the plurality of trapped ions having two frequency-separated states defining a qubit, computing a detuning frequency function and an amplitude function of a laser pulse to cause entangling interaction between a pair of trapped ions of the plurality of trapped ions, and performing a quantum computation in the quantum computer by applying a laser pulse having the computed detuning frequency function and the amplitude function to the pair of trapped ions for a gate duration.

Motional mode configuration for implementation of entangling gates in ion trap quantum computers

Techniques for the fabrication of electrodes and the shaping of glass dies or substrates are described to produce metal-on-glass ion traps. These ion traps may be configured to have open light access and high aspect trenches for the electrodes. For example, the glass substrate may be shaped to provide high numerical aperture (NA) light access by having angled cutouts, electrode structures with high aspect trenches, angled wire bonds for electrical connections, the angled wire bonds providing additional clear access by one or more laser beams, or a combination of any of these features. A quantum information processing (QIP) system is also described that may include an ion trap having any of these features.

Electrode fabrication and die shaping for metal-on-glass ion traps

The disclosure describes various aspects of techniques for cooling a chain of ions to near the combined ground state that does not grow with the number of ions in the chain. By addressing each ion individually and using each ion to cool a different motional mode, it is possible to cool the motional modes concurrently. In an example, a third of the total motional modes can be cooled at the same time. In an aspect, the techniques include generating a sideband cooling laser beam for each ion in the ion chain, concurrently cooling two or more motional modes associated with the ions in the ion chain using the respective sideband cooling laser beam until each of the two or more motional modes reaches a motional ground state, and performing a quantum computation using the ion chain after the two or more motional modes have reached the motional ground state.

Efficient cooling of ion chains for quantum computation

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. Coherent optical manipulations in such QIP systems may require interferometric stability between the incident laser beams and the atomic-based qubit (or other type of qubit) being addressed. Mechanical vibrations that affect the position of the qubit with respect to the incident laser beams directly contribute to optical phase differences and reduce fidelity. A technique is described herein that is used to mitigate or reduce optical phase differences arising from vibrations of the qubits with respect to the incident laser beams. This technique is generally applicable to any condition that results in such vibrations and systems needing interferometric stability and is compatible with cryogenic environments.

Vibration mitigation with optical folding

The disclosure describes various aspects of a vibrationally isolated cryogenic shield for local high-quality vacuum. More specifically, the disclosure describes a cryogenic vacuum system replicated in a small volume in a mostly room temperature ultra-high vacuum (UHV) system by capping the volume with a suspended cryogenic cold finger coated with a high surface area sorption material to produce a localized extreme high vacuum (XHV) or near-XHV region. The system is designed to ensure that all paths from outgassing materials to the control volume, including multiple bounce paths off other warm surfaces, require at least one bounce off of the high surface area sorption material on the cold finger. The outgassing materials can therefore be pumped before reaching the control volume. To minimize vibrations, the cold finger is only loosely, mechanically connected to the rest of the chamber, and the isolated along with the cryogenic system via soft vacuum bellows.

Vibrationally isolated cryogenic shield for local high-quality vacuum

The disclosure describes various aspects of a system with scalable and programmable coherent waveform generators. A network and digital-to-analog conversion (DAC) cards used by the network are described where each DAC card has a clock divider/replicator device with an input SYNC pin, a digital logic component, and one or more DAC components, and each output of the DAC components is used to control optical beams for a separate qubit of a quantum information processing (QIP) system. The network also includes a first distribution network to provide a clock signal to the clock divider/replicator device in the DAC cards, and a second distribution network to provide a start signal to the DAC cards, where the start signal is used by the digital logic component in the DAC card to assert the input SYNC pin when the start signal is asserted unless it is masked by the digital logic component.

Scalable and programmable coherent waveform generators

Systems and techniques are provided for pulse generation. A classical computing device may receive a program source code including quantum operations. The program source code may be compiled into a compiled program including the one or more quantum operations. Pulse shapes that a pulse shape library indicates corresponds to each of the quantum operations may be determined. Pulse instructions based on the one or more pulse shapes that the pulse shape library indicates corresponds to each of the quantum operations may be generated. Binary format instructions may be generated based on the pulse instructions. The binary format instruction may encode the pulse instructions in binary packets using a binary code of a field programmable gate array (FPGA) of a quantum computing device.

Pulse generation

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

A shaped central electrode is described that is placed between a pair of radio frequency (RF) rails of a trap configured to hold atomic-based qubits to control aspects of the operation of the trap. In one aspect, the shaping may involve forming a pinched region in the middle of the central electrode. The middle of the central electrode may correspond to the middle portion of the trap. The shaping of the central electrode may be achieved in different ways and may involve varying the width of the central electrode. The trap may be fabricated on a glass die or substrate, which itself may be shaped or not. The trap may be fabricated by various methods such as, but not limited to, patterned metal layers on glass or silicon substrates. A quantum information processing (QIP) system is also described that may include a trap having any of these features.

Shaped central electrode inside radio frequency rail to control aspects of an ion trap

Aspects of the present disclosure describe an atomic oven including a cathode, an anode that comprises a source material, and a power supply that provides a voltage between the cathode and the anode, wherein applying the voltage causes multiple electrons from the cathode to ablate the source material from the anode or locally heat the anode to cause source material to evaporate from the anode and, in both case, to produce a stream of ablated or evaporated particles that passes through an opening in the cathode.

Growing community of inventors

Takoma Park, MD, United States of America

Jason Madjdi Amini