Abstract: 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. To optimize the performance of QIP systems or quantum computers in terms of both fidelity and algorithm uptime or throughput, described are techniques to stabilize continuous and discrete errors from drifting and/or noisy secondary observables to achieve long term stable operation.

Abstract: 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 fast single-mode spectroscopy technique that may be used in trapped-ion QIP systems. A method is described that includes performing a first measurement scan (full scan) across all motional modes of an ion chain in a trap followed by a second measurement scan on a single motional mode of the motional modes (single-mode scan). The second measurement scan determines a frequency shift associated with the single motional mode, which is applied to adjust the frequencies of all the motional modes. An implementation of two-qubit gates for quantum computations is based on the adjusted frequencies. A quantum computer or QIP system is also described that is configured to implement and perform the method described above.

Abstract: Systems and methods for use in the implementation and/or operation of quantum information processing (QIP) systems or quantum computers, and more particularly, to benchmark-driven automation for tuning quantum computers are described. A method includes identifying a set of quantum gates and a number of experimental shots to perform a benchmark algorithm for active stabilization of one or more observables of the set of quantum gates and executing the benchmarking algorithm based on the set of quantum gates and the number of experimental shots. Moreover, in response to the benchmarking algorithm being successful, executing an algorithm on the quantum computer, and in response to the benchmarking algorithm being unsuccessful, iterating the benchmarking algorithm by adjusting the set of quantum gates until the benchmarking algorithm is successful or a preset number of iterations is reached.

Abstract: Aspects of the present disclosure may include a method and/or a system for applying a plurality of radio frequency (RF) fields to one or more surface electrode trapped ions, applying one or more Raman laser beams to the one or more surface electrode trapped ions, applying, for each of the plurality of RF fields, a plurality of compensation fields to identify a plurality of bright state probabilities for each of the plurality of RF fields, identifying a plurality of bright state curves each associated with the plurality of bright state probabilities for each of the plurality of RF fields, identifying a cancellation compensation field associated with the point of intersection.

Abstract: Aspects of the present disclosure may include a method and/or a system for applying, to one or more surface electrode trapped ions, a first electric field in a first direction, applying, to the one or more surface electrode trapped ions, a plurality of second electric fields in a second direction while applying the first electric field, wherein the second direction is substantially orthogonal to the first direction, measuring, for each of the plurality of second electric fields, a corresponding micromotion signal associated with the application of one or more of the first electric field or one of the plurality of second electric fields, identifying a maximum micromotion signal of a plurality of micromotion signals associated with the plurality of second electric fields, and identifying a compensation field associated with the maximum micromotion signal.

Abstract: 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.

Abstract: A method and system is provided for operating a quantum information processing (QIP) system, including a dual-space, single-species architecture for trapped-ion quantum information processing. An exemplary method of preparing the ions include i) applying a first optical beam to the plurality of ions to shelve at least a portion of the plurality of ions from a first state to a second state, ii) applying a second optical beam to the plurality of ions to deshelve the at least a portion of the plurality of ions from the second state to a third state, iii) applying a third optical beam to optically pump the at least a portion of the plurality of ions from the third state and to a fourth state, and iv) iteratively repeat i) to iii) to transition a remaining portion of the plurality of ions to the fourth state.

Abstract: 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. To optimize the performance of QIP systems or quantum computers in terms of both fidelity and algorithm uptime or throughput, described are techniques to stabilize continuous and discrete errors from drifting and/or noisy secondary observables to achieve long term stable operation.

Abstract: Aspects of the present disclosure may include a method and/or a system for selecting a first ion of the plurality of ions in the ion chain, selecting a second ion of the plurality of ions in the ion chain, applying a first carrier ?/2 pulse to the first ion, applying a first red sideband ? pulse to the first ion, applying a second red sideband ? pulse to the second ion, applying a second carrier ?/2 pulse to the second ion, and scanning a phase of the second carrier ?/2 pulse.

Abstract: A method and system is provided for operating a quantum information processing (QIP) system, including a dual-space, single-species architecture for trapped-ion quantum information processing. An exemplary method of preparing the ions include i) applying a first optical beam to the plurality of ions to shelve at least a portion of the plurality of ions from a first state to a second state, ii) applying a second optical beam to the plurality of ions to deshelve the at least a portion of the plurality of ions from the second state to a third state, iii) applying a third optical beam to optically pump the at least a portion of the plurality of ions from the third state and to a fourth state, and iv) iteratively repeat i) to iii) to transition a remaining portion of the plurality of ions to the fourth state.

Abstract: 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 fast single-mode spectroscopy technique that may be used in trapped-ion QIP systems. A method is described that includes performing a first measurement scan (full scan) across all motional modes of an ion chain in a trap followed by a second measurement scan on a single motional mode of the motional modes (single-mode scan). The second measurement scan determines a frequency shift associated with the single motional mode, which is applied to adjust the frequencies of all the motional modes. An implementation of two-qubit gates for quantum computations is based on the adjusted frequencies. A quantum computer or QIP system is also described that is configured to implement and perform the method described above.

Abstract: A system and method is provided for use in the implementation and/or operation of quantum information processing (QIP) systems, and more particularly, to design or configure an optimal side-band cooling operation for trapped ions. A method is described that involves applying a first cooling operation on the trapped ion chain and subsequently applying a second cooling operation on the trapped ion chain that includes applying to each cooling ion in the trapped ion chain, as part of a side-band cooling pulse sequence, at least one analysis pulse followed by a corresponding batch with one or more side-band cooling pulses, wherein each analysis pulse is configured to determine a detuning and pulse duration of the one or more side-band cooling pulses of the corresponding batch. A quantum computer or QIP system is also described that enables the operation of the method described above.

Abstract: Aspects of the present disclosure may include a method and/or a system for applying, to one or more surface electrode trapped ions, a first electric field in a first direction, applying, to the one or more surface electrode trapped ions, a plurality of second electric fields in a second direction while applying the first electric field, wherein the second direction is substantially orthogonal to the first direction, measuring, for each of the plurality of second electric fields, a corresponding micromotion signal associated with the application of one or more of the first electric field or one of the plurality of second electric fields, identifying a maximum micromotion signal of a plurality of micromotion signals associated with the plurality of second electric fields, and identifying a compensation field associated with the maximum micromotion signal.

Abstract: Aspects of the present disclosure may include a method and/or a system for applying a plurality of radio frequency (RF) fields to one or more surface electrode trapped ions, applying one or more Raman laser beams to the one or more surface electrode trapped ions, applying, for each of the plurality of RF fields, a plurality of compensation fields to identify a plurality of bright state probabilities for each of the plurality of RF fields, identifying a plurality of bright state curves each associated with the plurality of bright state probabilities for each of the plurality of RF fields, identifying a cancellation compensation field associated with the point of intersection.

Abstract: 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.

Abstract: Aspects of the present disclosure include methods and systems for modulating light sources including applying an optical beam, modulating one or more of an amplitude, a phase, or a frequency of the optical beam via an acousto-optic modulator (AOM), applying a sideband signal to a channel of an electro-optic modulator (EOM) to transform the optical beam to a carrier beam and at least two sideband beams, and providing one of the at least two sideband beams to one or more dual-space, single-species (DSSS) trapped ions of the QIP system to transition the one or more DSSS trapped ions from a first state to a second state.