Critical assessment of two-qubit post-Markovian master equations

Campbell, Steve; Smirne, A.; Mazzola, L.; Lo Gullo, Nicola; Vacchini, B.; Busch, Thomas; Paternostro, Mauro

Critical assessment of two-qubit post-Markovian master equations

Files

3553.pdf(437.47 KB)

Published Version

Date

2012

Authors

Campbell, Steve

Smirne, A.

Mazzola, L.

Lo Gullo, Nicola

Vacchini, B.

Busch, Thomas

Paternostro, Mauro

Publisher

American Physical Society

Published Version

10.1103/PhysRevA.85.032120

Abstract

A post-Markovian master equation has been recently proposed as a tool to describe the evolution of a system coupled to a memory-keeping environment [A. Shabani and D. A. Lidar, Phys. Rev. A 71, 020101 ( R) ( 2005)]. For a single qubit affected by appropriately chosen environmental conditions, the corresponding dynamics is always legitimate and physical. Here we extend such a situation to the case of two qubits, only one of which experiences the environmental effects. We show how, despite the innocence of such an extension, the introduction of the second qubit should be done cum grano salis to avoid consequences such as the breaking of the positivity of the associated dynamical map. This hints at the necessity of using care when adopting phenomenologically derived models for evolutions occurring outside the Markovian framework.

Keywords

Dynamical semigroups , Quantum , Systems

Citation

Campbell, S., Smirne, A., Mazzola, L., Lo Gullo, N., Vacchini, B., Busch, T. and Paternostro, M. (2012) 'Critical assessment of two-qubit post-Markovian master equations', Physical Review A, 85(3), 032120 (6pp). doi: 10.1103/PhysRevA.85.032120