Observation of non-Markovian micro-mechanical Brownian motion

TL;DR

This paper uses an opto-mechanical resonator to reveal non-Ohmic, non-Markovian spectral densities of a heat bath, challenging common assumptions and advancing understanding of decoherence in quantum systems.

Contribution

It demonstrates a method to characterize non-Markovian dynamics in quantum Brownian motion using opto-mechanical systems, revealing spectral densities that differ from traditional models.

Findings

Spectral density is highly non-Ohmic.

Dynamics are non-Markovian.

Method enables open system identification.

Abstract

All physical systems are to some extent open and interacting with their environment. This insight, basic as it may seem, gives rise to the necessity of protecting quantum systems from decoherence in quantum technologies and is at the heart of the emergence of classical properties in quantum physics. The precise decoherence mechanisms, however, are often unknown for a given system. In this work, we make use of an opto-mechanical resonator to obtain key information about spectral densities of its condensed-matter heat bath. In sharp contrast to what is commonly assumed in high-temperature quantum Brownian motion describing the dynamics of the mechanical degree of freedom, based on a statistical analysis of the emitted light, it is shown that this spectral density is highly non-Ohmic, reflected by non-Markovian dynamics, which we quantify. We conclude by elaborating on further applications of opto-mechanical systems in open system identification.