Microscopic theory of a non-equilibrium open bosonic chain

TL;DR

This paper develops a microscopic approach to construct Lindblad dissipators for open quantum bosonic chains, revealing non-local effects and deriving transport properties consistent with Landauer's formula and Onsager's relations.

Contribution

It introduces a method to derive non-local Lindblad dissipators from microscopic system-bath interactions in a bosonic chain, linking microscopic dynamics to macroscopic transport laws.

Findings

Effective dissipators are inherently non-local despite local bath coupling.

Particle and energy currents follow Landauer's formula structure.

Currents satisfy Onsager's reciprocal relations under small gradients.

Abstract

Quantum master equations form an important tool in the description of transport problems in open quantum systems. However, they suffer from the difficulty that the shape of the Lindblad dissipator depends sensibly on the system Hamiltonian. Consequently, most of the work done in this field has focused on phenomenological dissipators which act locally on different parts of the system. In this paper we show how to construct Lindblad dissipators for quantum many-body systems starting from a microscopic theory of the system-bath interaction. We consider specifically a one-dimensional bosonic tight-binding chain connected to two baths at the first and last site, kept at different temperatures and chemical potentials. We then shown that, even though the bath coupling is local, the effective Lindblad dissipator stemming from this interaction is inherently non-local, affecting all normal modes of the system. We then use this formalism to study the current of particles and energy through the system and find that they have the structure of Landauer's formula, with the bath spectral density playing the role of the transfer integral. Finally, we consider infinitesimal temperature and chemical potential gradients and show that the currents satisfy Onsager's reciprocal relations, which is a consequence of the fact that the microscopic quantum dynamics obeys detailed balance.