TY - JOUR

T1 - Quantum speed limit for robust state characterization and engineering

AU - Kobayashi, Kohei

AU - Yamamoto, Naoki

N1 - Publisher Copyright:
© 2020 American Physical Society.

PY - 2020/10/15

Y1 - 2020/10/15

N2 - In this paper we propose to use a quantum speed limit (QSL) as a measure of robustness of states, defining a state with a bigger QSL as more robust. From this perspective, it is important to have an explicitly computable QSL, because then we can formulate an engineering problem of the Hamiltonian that makes a target state robust against decoherence. Hence we derive an 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 the QSL, is demonstrated with several examples.

AB - In this paper we propose to use a quantum speed limit (QSL) as a measure of robustness of states, defining a state with a bigger QSL as more robust. From this perspective, it is important to have an explicitly computable QSL, because then we can formulate an engineering problem of the Hamiltonian that makes a target state robust against decoherence. Hence we derive an 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 the QSL, is demonstrated with several examples.

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U2 - 10.1103/PhysRevA.102.042606

DO - 10.1103/PhysRevA.102.042606

M3 - Article

AN - SCOPUS:85093357467

SN - 2469-9926

VL - 102

JO - Physical Review A

JF - Physical Review A

IS - 4

M1 - 042606

ER -