Time Evolution of Harmonic Oscillator Thermal Momentum Superposition States

TL;DR

This paper investigates how thermal states of a mirror evolve over time when released from a harmonic trap and subjected to momentum superpositions, revealing that coherence persists despite thermal noise and that measurements can be insensitive to temperature.

Contribution

It demonstrates that thermal decoherence can occur without dissipation and that measurements can remain unaffected by temperature, clarifying a controversy in quantum decoherence studies.

Findings

Thermal states lose interference patterns but retain coherence.

Decoherence can occur without dissipation.

Measurements can be insensitive to temperature effects.

Abstract

The time evolution of thermal states of a mirror released from a tight harmonic trap is studied. After the release no dissipation is assumed to be present and the mirror is, after a time delay, kicked into a momentum superposition state. The thermal character of the initial state washes out the telltale interference patterns of the superposition but no loss of coherence is found. This investigation resolves a controversy about decoherence--without--dissipation and shows that entrained measurements can be surprisingly insensitive to temperature effects.