Microscopic decay dynamics and complex eigenvalue in periodically driven open quantum system

Kenichi Noba (Osaka Prefecture University)

Abstract:
By analyzing the complex eigenvalues of the Floquet Hamiltonian of periodically driven open quantum systems, we obtain characteristic properties of the decay dynamics[1,2]. In the present study, we consider a microscopic model in which an impurity driven by an external periodic field is coupled to a one-dimensional chain. In the complex energy plane, there appears an infinite number of eigenvalues of the Floquet Hamiltonian on different Riemann sheets as a result of nonlinearity in the dispersion equation. By a contour deformation technique, we can pick up the eigenvalue which contributes to the decay dynamics of the system. We demonstrate that the decay dynamics are qualitatively modified at points where the eigenvalue changes its character as the field parameter is varied.

[1] N. Yamada, K. Noba, S. Tanaka, T. Petrosky, Phys. Rev. B 86, 014302 (2012) 
[2] K. Noba, N. Yamada, Y. Uesaka, S. Tanaka, T. Petrosky, J. Phys. A: Math. Theor 47, 385302 (2014)