Entanglement Dynamics of Separable Squeezed States in Finite Memory Structured Reservoir

TL;DR

This study explores how separable squeezed states can develop entanglement in structured, non-Markovian reservoirs, revealing mechanisms like entanglement revival and oscillations that are absent in simpler Markovian models.

Contribution

It demonstrates the emergence of entanglement from initially separable states in structured environments using advanced Gaussian and non-Markovian analysis methods.

Findings

Identified detuning conditions that freeze entanglement trajectories.

Observed entanglement birth, death, and revival from orthogonal inputs.

Discovered integer-locked beating with square-wave oscillations due to periodic detuning.

Abstract

Entanglement in continuous-variable Gaussian systems is a key resource, and common reservoirs can both suppress and generate correlations. Existing work focused on pre-entangled states or Markovian baths, leaving open whether separable squeezed inputs entangle in structured environments or under modulation. We study two bosonic modes coupled to a common reservoir, each initialized in a separable squeezed vacuum. Dynamics are analyzed utilizing Gaussian covariance methods, evolved under approximate Non-Markovian quantum state diffusion (QSD), finite-temperature pseudomode embeddings, and Bures-based non-Markovian diagnostics. We identify three mechanisms absent in Markovian dynamics: (1) A detuning condition that freezes entanglement trajectories across reservoir correlation times; (2) birth, death, and revival of entanglement from orthogonal inputs; and (3) integer-locked beating with square-wave oscillations produced by periodic detuning. All mechanisms persist at finite temperature, with deviations bounded within 5% in cryogenic regimes and 20% at moderate occupations. These deviation bounds align with cryogenic cavity, phononic, and optomechanical platforms, where structured spectral densities and detuning modulation are already accessible. Structured reservoirs are shown to emerge as tunable entanglement resources for continuous-variable quantum technologies.