Exact dynamics and bound states of a cavity coupled to a two-dimensional reservoir

TL;DR

This paper presents an exact analytical study of bound states in a 2D coupled-cavity array, demonstrating their potential for robust quantum information storage and revealing non-Markovian effects in photonic lattices.

Contribution

It introduces a scheme for quantum memory using bound states in a 2D cavity array, with exact solutions showing conditions for optimal storage and non-Markovian dynamics.

Findings

Bound states enable perfect quantum storage in weak coupling.

Strong coupling causes oscillations and reduces fidelity.

Results are valid at finite temperatures and show non-Markovian features.

Abstract

We demonstrate a robust scheme for quantum information storage based on bound states in a two-dimensional coupled-cavity array. When a target cavity is tuned to resonance with the array, a bound state in the continuum (BIC) emerges, coexisting with two conventional bound states outside the band. The resulting dynamics reflects a delicate interplay between these bound states, which can be fully captured through exact analytical solutions. In the weak-coupling regime, the BIC dominates, enabling perfect and persistent information storage. At stronger coupling, all bound states contribute, leading to oscillatory behavior and reduced storage fidelity. These results, valid at both zero and finite reservoir temperatures and further supported by a single-particle framework, reveal distinctive non-Markovian features in continuous-variable systems and highlight the potential of photonic lattices for scalable all-optical decoherence-free quantum memory platforms.