We investigate the Landau-Zener tunneling (LZT) of a self-interacting two-level system in which coupling between levels is nonreciprocal. In such non-Hermitian system, when energy bias two adjusted very slowly, i.e., adiabatic limit, we find that quantum state can still closely follow eigenstate solution until it encounters exceptional points (EPs) at eigenvalues and their corresponding eigenve...

Abstract We employ the Markov approximation and well-known Fresnel-
integral to derive in "one-line" familiar expression for Landau-Zener
transition probability. Moreover, we provide numerical as well analytical
justifications our approach, identify three characteristic motions of the
probability amplitude complex plane.