Holstein mechanism in single-site model with unitary evolution

TL;DR

This paper explores the Holstein mechanism in a single-site quantum system, revealing a quantum phase transition characterized by different decay behaviors and a transition from non-Markovian to Markovian dynamics.

Contribution

It introduces a detailed analysis of the Holstein mechanism under unitary evolution in a single-electron system, highlighting a quantum phase transition and non-Markovian effects.

Findings

Identification of a quantum phase transition

Distinct short-time and long-time decay behaviors

Transition from non-Markovian to Markovian dynamics

Abstract

We investigate the Holstein mechanism in a single-electron (one-site) system, where unitary evolution intrinsically involves both fermion and boson operators under nonadiabatic conditions. The resulting unitary dynamics and boson-frequency dependence reveal a quantum phase transition, evidenced by distinct short-time (power-law decay) and long-time (exponential decay) behaviors, which are manifested in the polaronic shift, bosonic energy, and dynamics of reduced density matrix. This observation is consistent with a non-Markovian to Markovian transition.