Disentanglement and Decoherence without dissipation at non-zero temperatures

TL;DR

This paper demonstrates that disentanglement can occur at high temperatures even with negligible dissipation, highlighting a fundamental difference from decoherence where temperature effects grow exponentially over time.

Contribution

It reveals that disentanglement can happen without dissipation at non-zero temperatures and distinguishes its behavior from decoherence.

Findings

Disentanglement occurs at high T with minimal dissipation.

Temperature effects on decoherence grow exponentially over time.

Disentanglement's temperature effect remains constant over time.

Abstract

Decoherence is well understood, in contrast to disentanglement. According to common lore, irreversible coupling to a dissipative environment is the mechanism for loss of entanglement. Here, we show that, on the contrary, disentanglement can in fact occur at large enough temperatures $T$ even for vanishingly small dissipation (as we have shown previously for decoherence). However, whereas the effect of $T$ on decoherence increases exponentially with time, the effect of $T$ on disentanglement is constant for all times, reflecting a fundamental difference between the two phenomena. Also, the possibility of disentanglement at a particular $T$ increases with decreasing initial entanglement.