Dynamical decoupling sequences for multi-qubit dephasing suppression and long-time quantum memory

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Author(s)
Paz-Silva, GA
Lee, SW
Green, TJ
Viola, L
Griffith University Author(s)
Year published
2016
Metadata
Show full item recordAbstract
Weconsider a class of multi-qubit dephasing models that combine classical noise sources and linear
coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical
decoupling pulses. Building on a general transfer filter-function framework for open-loop control, we
provide an exact representation of the controlled dynamics for arbitrary stationary non-Gaussian
classical and quantum noise statistics, with analytical expressions emerging when all dephasing
sources are Gaussian. This exact characterization is used to establish two main results. First, we
construct multi-qubit sequences that ensure maximum ...
View more >Weconsider a class of multi-qubit dephasing models that combine classical noise sources and linear coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical decoupling pulses. Building on a general transfer filter-function framework for open-loop control, we provide an exact representation of the controlled dynamics for arbitrary stationary non-Gaussian classical and quantum noise statistics, with analytical expressions emerging when all dephasing sources are Gaussian. This exact characterization is used to establish two main results. First, we construct multi-qubit sequences that ensure maximum high-order error suppression in both the time and frequency domain and that can be exponentially more efficient than existing ones in terms of total pulse number. Next, we show how long-time multi-qubit storage may be achieved by meeting appropriate conditions for the emergence of a fidelity plateau under sequence repetition, thereby generalizing recent results for single-qubit memory under Gaussian dephasing. In both scenarios, the key step is to endow multi-qubit sequences with a suitable displacement anti-symmetry property, which is of independent interest for applications ranging from environment-assisted entanglement generation to multi-qubit noise spectroscopy protocols.
View less >
View more >Weconsider a class of multi-qubit dephasing models that combine classical noise sources and linear coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical decoupling pulses. Building on a general transfer filter-function framework for open-loop control, we provide an exact representation of the controlled dynamics for arbitrary stationary non-Gaussian classical and quantum noise statistics, with analytical expressions emerging when all dephasing sources are Gaussian. This exact characterization is used to establish two main results. First, we construct multi-qubit sequences that ensure maximum high-order error suppression in both the time and frequency domain and that can be exponentially more efficient than existing ones in terms of total pulse number. Next, we show how long-time multi-qubit storage may be achieved by meeting appropriate conditions for the emergence of a fidelity plateau under sequence repetition, thereby generalizing recent results for single-qubit memory under Gaussian dephasing. In both scenarios, the key step is to endow multi-qubit sequences with a suitable displacement anti-symmetry property, which is of independent interest for applications ranging from environment-assisted entanglement generation to multi-qubit noise spectroscopy protocols.
View less >
Journal Title
New Journal of Physics
Volume
18
Copyright Statement
©2016 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This is an Open Access article distributed under the terms of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) License (https://creativecommons.org/licenses/by/3.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Subject
Physical Sciences not elsewhere classified
Physical Sciences