Room 117
Non-Markovianity Hierarchy of Gaussian Processes and Quantum Amplification
Prathik Cherian J.
IMSc
We investigate the dynamics of Gaussian states of continuous variable systems under Gaussianity-preserving channels. We introduce a hierarchy of such evolutions encompassing Markovian and weakly and strongly non-Markovian processes and provide simple criteria to distinguish between the classes, based on the degree of positivity of intermediate Gaussian maps. We present an intuitive classification of all one-mode Gaussian channels according to their non-Markovianity degree and show that weak non-Markovianity has an operational significance, as it leads to a temporary phase-insensitive amplification of Gaussian inputs beyond the fundamental quantum limit. Explicit examples and applications are discussed.
Paper link: journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.050401
Link to a related (but previous) work: journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.070401
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