Neural quantum states for emitter dynamics in waveguide QED

TL;DR

This paper introduces a neural quantum state method to simulate the dynamics of quantum emitters in waveguide QED systems, especially when permutation symmetry is absent, enabling efficient analysis of complex open quantum many-body phenomena.

Contribution

The authors extend the time-dependent neural quantum state framework to open systems and benchmark its effectiveness against tensor-network methods in waveguide QED scenarios.

Findings

t-NQS performs competitively with tensor-network methods.

The approach effectively handles systems without permutation symmetry.

Demonstrates potential for studying out-of-equilibrium open quantum systems.

Abstract

Quantum emitters coupled to one-dimensional waveguides constitute a paradigmatic quantum-optical platform for exploring collective phenomena in open quantum many-body systems. For appropriately spaced emitters, they realize the Dicke model, whose characteristic permutation symmetry allows for efficient exact solutions featuring superradiance. When the emitters are arbitrarily spaced, however, this symmetry is lost and general analytical solutions are no longer available. In this work, we introduce a novel numerical method to study the dynamics of such systems by extending the time-dependent neural quantum state (t-NQS) framework to open quantum systems. We benchmark our approach across a range of waveguide QED settings and compare its performance with tensor-network calculations. Our results demonstrate that the t-NQS approach is competitive with other numerical methods and highlight the potential of t-NQSs for studying open quantum many-body systems out of equilibrium.