arXiv subjects

H. Y. Ma

Publications and source records attributed to H. Y. Ma.

2 recordsLinked to original sources

arXiv2023

Dynamics Reflects Quantum Phase Transition of Rabi Model

As the simplest and most fundamental model describing the interaction between light and matter, a breakdown in the rotating wave approximation of the Rabi model leads to phase transition versus coupling strength when the frequency of the qubit greatly surpasses that of the oscillator. Besides the phase transition revealed in the ground state, we show that the dynamics of physical quantities can reflect such a phase transition for this model. In addition to the excitation of the bosonic field in the ground state, we show that the witness of inseparability (entanglement), mutual information, quantum Fisher information, and the variance of cavity quadrature can be employed to detect the phase transition in quench. We also reveal the negative impact of temperature on checking the phase transition by quench. This model can be implemented using trapped ions, superconducting artificial atoms coupled bosonic modes, and quantum simulations. By reflecting the phase transition in a fundamental quantum optics model without imposing the thermodynamic limit, this work offers an idea to explore phase transitions by non-equilibrium process for open quantum systems.

quant-ph↗

arXiv2022

Dynamics Reflect Gapless Edge Modes for Topological Superconductor

We focus on the dynamical feature for a $p$-wave superconductor model in different parameter regions in terms of the appearance of gapless edge modes in reel geometry. Firstly, we show the parameter region with gapless edge modes versus a parameter and quasi-momentum. The parameter diagram can be reflected by the expectations of Pauli matrices in global manners. In another view, the dynamical feature of the excitation behave differently in the parameter regions with topological gapless edge modes and not. And the cusps of dynamical return rate vanish as the parameter pass the boundary in the parameter region slowly enough. It is found that the dynamics in the parameter region with gapless edge modes behaves differently to that without edge modes and related mostly to the eigenenergy gap between the pre-and post-quench eigenstates. The cusps of the dynamical return rate behave robustly against the noise in the lattice until localization behavior dominates. This work benefits detecting topological edge modes by dynamical manners.

cond-mat.supr-con↗