Heralded nonlocal quantum gates for distributed quantum computation in a decoherence-free subspace

Fuente: arXiv
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Main Authors: Su, Wanhua, Qin, Wei, Miranowicz, Adam, Li, Tao, Nori, Franco
Format: Preprint
Published: 2023
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author Su, Wanhua
Qin, Wei
Miranowicz, Adam
Li, Tao
Nori, Franco
author_facet Su, Wanhua
Qin, Wei
Miranowicz, Adam
Li, Tao
Nori, Franco
contents We propose a heralded protocol for implementing nontrivial quantum gates on two stationary qubits coupled to spatially separated cavities. By dynamically controlling the evolution of the composite system, nonlocal two-qubit quantum (e.g., CPHASE and CNOT) gates can be achieved without real excitations of either cavity modes or atoms. The success of our protocol is conditioned on projecting an auxiliary atom onto a postselected state, which simultaneously removes various detrimental effects of dissipation on the gate fidelity. In principle, the success probability of the gate can approach unity as the single-atom cooperativity becomes sufficiently large.Furthermore, we show its application for implementing single- and two-qubit gates within a decoherence-free subspace that is immune to a collective dephasing noise. This faithful, heralded, and nonlocal protocol could, therefore, be useful for distributed quantum computation and scalable quantum networks.
format Preprint
id arxiv_https___arxiv_org_abs_2305_00642
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Heralded nonlocal quantum gates for distributed quantum computation in a decoherence-free subspace
Su, Wanhua
Qin, Wei
Miranowicz, Adam
Li, Tao
Nori, Franco
Quantum Physics
We propose a heralded protocol for implementing nontrivial quantum gates on two stationary qubits coupled to spatially separated cavities. By dynamically controlling the evolution of the composite system, nonlocal two-qubit quantum (e.g., CPHASE and CNOT) gates can be achieved without real excitations of either cavity modes or atoms. The success of our protocol is conditioned on projecting an auxiliary atom onto a postselected state, which simultaneously removes various detrimental effects of dissipation on the gate fidelity. In principle, the success probability of the gate can approach unity as the single-atom cooperativity becomes sufficiently large.Furthermore, we show its application for implementing single- and two-qubit gates within a decoherence-free subspace that is immune to a collective dephasing noise. This faithful, heralded, and nonlocal protocol could, therefore, be useful for distributed quantum computation and scalable quantum networks.
title Heralded nonlocal quantum gates for distributed quantum computation in a decoherence-free subspace
topic Quantum Physics
url https://arxiv.org/abs/2305.00642