Quantum decoherence of an anharmonic oscillator monitored by a Bose-Einstein condensate

TL;DR

This paper investigates how a quantum anharmonic oscillator's coherence is affected by continuous monitoring via a Bose-Einstein condensate, revealing complex decoherence behaviors including Gaussian and power-law decay regimes.

Contribution

It provides a detailed analysis of decoherence dynamics in an anharmonic oscillator monitored by a BEC, including both classical and quantum regimes with analytical expressions.

Findings

Decoherence exhibits initial Gaussian decay followed by power-law decay.

Characteristic time scales for decoherence regimes are identified.

Quantum analysis shows algebraic decay of coherence over time.

Abstract

The dynamics of a quantum anharmonic oscillator whose position is monitored by a Bose-Einstein condensate (BEC) trapped in a symmetric double well potential is studied. The (non-exponential) decoherence induced on the oscillator by the measuring device is analysed. A detailed quasiclassical and quantum analysis is presented. In the first case, for an arbitrary initial coherent state, two different decoherence regimes are observed: An initial Gaussian decay followed by a power law decay for longer times. The characteristic time scales of both regimes are reported. Analytical approximated expressions are obtained in the full quantum case where algebraic time decay of decoherence is observed.