[Seminar] Prof. Naomichi Hatano "Non-Hermiticity and non-Markovianity of open quantum systems"

Speaker

Prof. Naomichi Hatano / The University of Tokyo

Title

Non-Hermiticity and non-Markovianity of open quantum systems

Abstract

The open quantum system is a part of a bigger closed system; it is typically a small but complex system (often called the system) surrounded by a large but simple system (often called the environment). I here report our new findings about the non-Hermiticity and non-Markovianity of open quantum systems.

Since the system exchanges energy and probability with the environment, the effective Hamiltonian of the system is generally non-Hermitian. Complex eigenvalues of all resonant states are given by the non-Hermitian Hamiltonian. For one-body scattering problem, I report our new resolution of unity that comprises all point spectra including all complex eigenvalues.

Another interesting feature of open quantum systems is their dynamics. Since the environment functions as a memory, the dynamics of the system is generally non-Markovian with the memory kernel coming from the Green's function of the environment. Again for one-body problem, I report our new findings about the power-law decay in the short- and long-term regimes of the dynamics of the system.

Profile: Naomichi Hatano is a professor at U. Tokyo, working on fundamental aspects of statistical and quantum physics. He is best known as one of the initiators of non-Hermitian quantum mechanics for his proposal of a model called the Hatano-Nelson model back in 1990s. He has recently worked on non-Hermiticity of open quantum systems and now is delving into their non-Markovian dynamics.

Naomichi is hosted by OIST's Visiting Program (TSVP).

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Meeting ID: 912 8687 6233
Passcode: 124722