Ionq, Inc.

Duke University

Reinhold Blumel

Yunseong Nam

Nikodem Grzesiak

Jungsang Kim

Jason Madjdi Amini

Jonathan Albert Mizrahi

Jeremy Matthew Sage

Kenneth Wright

Ming Li

Andrii Maksymov

Hermann Uys

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

Embodiments described herein are generally related to a method and a system for constructing and delivering a pulse to perform an entangling gate operation between two trapped ions during a quantum computation, and more specifically, to a method of demodulating and spline interpolating a pulse that can be practically implemented in the system while increasing the fidelity of the entangling gate operation, or the probability that at least two ions are in the intended qubit state(s) after performing the entangling gate operation between the two ions.

Demodulation and smoothing of amplitude, frequency, and phase modulated pulses for optimal implementation of entangling gates in ion trap quantum computers

A method for performing an entangling operation between trapped ions in a quantum computer includes selecting an amount of infidelity that is allowed in an entangling operation between two trapped ions in a quantum computer, computing a pulse function of a pulse to be applied to each of the two trapped ions based on gate operation conditions and the selected amount of infidelity, generating the pulse based on the computed pulse function, and applying the generated pulse to each of the two trapped ions to perform the entangling operation between the two trapped ions.

Fast two-qubit gates on a trapped-ion quantum computer

A method of performing an entangling gate operation using a quantum computer system includes configuring, by a classical computer, an amplitude function of an amplitude-modulated laser pulse over a plurality of time segments to cause entangling interaction between a pair of trapped ions of a plurality of trapped ions, each of the plurality of trapped ions having two frequency-separated states defining a qubit, where the amplitude function in each time segment is splined using a set of basis functions and associated control parameters, and performing an entangling gate operation between the pair of trapped ions by applying, by a system controller, an amplitude-modulated laser pulse having the configured amplitude function to the pair of trapped ions.

Amplitude modulated pulses for implementation of entangling gates in ion trap quantum computers

A method of performing a computation using an ion trap quantum computer includes computing a detuning frequency function and an amplitude function of a laser pulse to cause entangling interaction between a pair of trapped ions of a plurality of trapped ions, each of the plurality of trapped ions having two frequency-separated states defining a qubit, splining the computed detuning frequency function of the laser pulse, modifying the computed amplitude function of the laser pulse based on the splined detuning frequency function, and applying a modified laser pulse having the splined detuning frequency function and the modified amplitude function to each trapped ion in the pair of trapped ions.

Amplitude, frequency, and phase modulated entangling gates for ion trap quantum computers

A method of performing a computation using a quantum computer includes generating a plurality of laser pulses used to be individually applied to each of a plurality of trapped ions that are aligned in a first direction, each of the trapped ions having two frequency-separated states defining a qubit, and applying the generated plurality of laser pulses to the plurality of trapped ions to perform simultaneous pair-wise entangling gate operations on the plurality of trapped ions. Generating the plurality of laser pulses includes adjusting an amplitude value and a detuning frequency value of each of the plurality of laser pulses based on values of pair-wise entanglement interaction in the plurality of trapped ions that is to be caused by the plurality of laser pulses.

Amplitude, frequency, and phase modulated simultaneous entangling gates for trapped-ion quantum computers

A method of performing simultaneous entangling gate operations in a trapped-ion quantum computer includes selecting a gate duration value and a detuning frequency of pulses to be individually applied to a plurality of participating ions in a chain of trapped ions to simultaneously entangle a plurality of pairs of ions among the plurality of participating ions by one or more predetermined values of entanglement interaction, determining amplitudes of the pulses, based on the selected gate duration value, the selected detuning frequency, and the frequencies of the motional modes of the chain of trapped ions, generating the pulses having the determined amplitudes, and applying the generated pulses to the plurality of participating ions for the selected gate duration value. Each of the trapped ions in the chain has two frequency-separated states defining a qubit, and motional modes of the chain of trapped ions each have a distinct frequency.

Simultaneously entangling gates for trapped-ion quantum computers

A method of performing a computation using a quantum computer includes generating a first laser pulse and a second laser pulse to cause entanglement interaction between a first trapped ion and a second trapped ion of a plurality of trapped ions that are aligned in a first direction, each of the plurality of trapped ions having two frequency- separated states defining a qubit, and applying the generated first laser pulse to the first trapped ion and the generated second laser pulse to the second trapped ion. Generating the first laser pulse and the second laser pulse includes stabilizing the entanglement interaction between the first and second trapped ions against fluctuations in frequencies of collective motional modes of the plurality of trapped ions in a second direction that is perpendicular to the first direction.

Stabilization of entangling gates for trapped-ion quantum computers

A method of performing a computation using a quantum computer includes generating a first laser pulse and a second laser pulse to cause entanglement interaction between a first trapped ion and a second trapped ion of a plurality of trapped ions that are aligned in a first direction, each of the plurality of trapped ions having two frequency-separated states defining a qubit, and applying the generated first laser pulse to the first trapped ion and the generated second laser pulse to the second trapped ion. Generating the first laser pulse and the second laser pulse includes stabilizing the entanglement interaction between the first and second trapped ions against fluctuations in frequencies of collective motional modes of the plurality of trapped ions in a second direction that is perpendicular to the first direction.

A method of performing an entangling operation between two trapped ions in a quantum computer includes selecting a gate duration value of a pulse to be applied to a first ion and a second ion in a chain of trapped ions, determining one or more tones of the pulse, each tone comprising an amplitude value and a detuning frequency value, based on the selected gate duration value and frequencies of the motional modes of the chain of trapped ions, generating the pulse having the one or more tones, each tone comprising the determined amplitude and the determined detuning frequency values, and applying the generated pulse to the first and second ions for the gate duration value. Each of the trapped ions has two frequency-separated states defining a qubit, and motional modes of the chain of trapped ions each have a distinct frequency.

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Middletown, CT, United States of America

Reinhold Blumel