Polarized Houston State Framework for Nonequilibrium Driven Open Quantum Systems

TL;DR

The paper introduces the polarized Houston basis, a new theoretical approach for accurately modeling nonequilibrium dynamics in driven open quantum systems, reducing unphysical artifacts and improving excitation descriptions.

Contribution

It presents the polarized Houston basis as a novel extension of Houston states that incorporates polarization effects, enhancing the modeling of driven open quantum systems.

Findings

Reduces spurious Bloch-state excitations

Suppresses virtual transitions in standard Houston approaches

Decreases unphysical DC currents in insulating systems

Abstract

We introduce a new theoretical framework -- the polarized Houston basis -- to model nonequilibrium dynamics in driven open quantum systems, formulated for use within the quantum master equation. This basis extends conventional Houston states by incorporating field-induced polarization effects, enabling a more accurate description of excitation dynamics under external driving. Using a one-dimensional dimer-chain model, we examine band population dynamics through projections onto polarized Houston states, original Houston states, and naive Bloch states. We find that the polarized Houston basis significantly suppresses spurious Bloch-state excitations and virtual transitions present in standard Houston approaches, allowing for a cleaner extraction of real excitations. When implemented in the relaxation time approximation of the quantum master equation, this formalism also yields a substantial reduction of unphysical DC currents in insulating systems. Our results highlight the polarized Houston basis as a powerful tool for simulating nonequilibrium phenomena in light-driven open quantum materials.