Excitation dynamics in chain-mapped environments

TL;DR

This paper investigates how excitations propagate in chain-mapped environments of open quantum systems, revealing key environmental features like localization and stationary currents through analysis of spectral density and temperature effects.

Contribution

It provides new insights into excitation transport in chain-mapped environments, linking spectral density, temperature, and environmental dynamics with phenomena like localization and currents.

Findings

Identification of localization effects in excitation transport

Relationship between spectral density shape and excitation dynamics

Observation of stationary currents and percolation phenomena

Abstract

The chain mapping of structured environments is a most powerful tool for the simulation of open quantum system dynamics. Once the environmental bosonic or fermionic degrees of freedom are unitarily rearranged into a one dimensional structure, the full power of Density Matrix Renormalization Group (DMRG) can be exploited. Beside resulting in efficient and numerically exact simulations of open quantum systems dynamics, chain mapping provides an unique perspective on the environment: the interaction between the system and the environment creates perturbations that travel along the one dimensional environment at a finite speed, thus providing a natural notion of light-, or causal-, cone. In this work we investigate the transport of excitations in a chain-mapped bosonic environment. In particular, we explore the relation between the environmental spectral density shape, parameters and temperature, and the dynamics of excitations along the corresponding linear chains of quantum harmonic oscillators. Our analysis unveils fundamental features of the environment evolution, such as localization, percolation and the onset of stationary currents.