Quantum speed limit for robust state characterization and engineering

• URL: http://arxiv.org/abs/2007.02788v1
• Date: Mon, 6 Jul 2020 14:43:47 GMT
• Title: Quantum speed limit for robust state characterization and engineering
• Authors: Kohei Kobayashi and Naoki Yamamoto
• Abstract summary: We use a quantum speed limit (QSL) as a measure of robustness of states. We derive a new explicitly-computable QSL that is applicable to general Markovian open quantum systems.
• Score: 1.1110435360741175
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: In this paper, we propose a concept to use a quantum speed limit (QSL) as a measure of robustness of states, defining that a state with bigger QSL is more robust. In this perspective, it is important to have an explicitly-computable QSL, because then we can formulate an engineering problem of Hamiltonian that makes a target state robust against decoherence. Hence we derive a new explicitly-computable QSL that is applicable to general Markovian open quantum systems. This QSL is tighter than another explicitly-computable QSL, in an important setup such that decoherence is small. Also the Hamiltonian engineering problem with this QSL is a quadratic convex optimization problem, and thus it is efficiently solvable. The idea of robust state characterization and the Hamiltonian engineering, in terms of QSL, is demonstrated with several examples.

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