Eur. Phys. J. D (2014) 68: 189
https://doi.org/10.1140/epjd/e2014-50188-1

Regular Article

𝒫𝒯-symmetry-breaking induced suppression of tunneling in a driven non-Hermitian two-level system

¹ Department of Physics, Jishou University, Jishou 416000, P.R. China
² State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, P.R. China
³ School of Physics and Electronic Engineering, Hainan Normal University, Haikou 571158, P.R. China

^a e-mail: hhzhong115@163.com

Received: 8 March 2014
Received in final form: 8 April 2014
Published online: 24 July 2014

Abstract

We investigate the effect of parity-time (𝒫𝒯) symmetry on quantum tunneling dynamics for a periodically driven 𝒫𝒯-symmetric non-Hermitian two-level system. We find that the quantum tunneling between two levels can be suppressed in a wide range of parameters in comparison with the Hermitian case, which is caused by the 𝒫𝒯-symmetry-breaking. By employing the high-frequency Floquet approach, the parametric dependence of the spontaneous 𝒫𝒯-symmetry-breaking transition is analytically and numerically explored. It is revealed that we can manipulate the 𝒫𝒯 symmetry by tuning the driving amplitude and frequency. Our results provide a promising approach for manipulating the 𝒫𝒯 symmetry by applying a periodic driving field.