title: Observation of non-Markovian micromechanical Brownian motion.
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.
authors.affiliation: 1] Kavli Institute of Nanoscience, Delft University of Technology, Delft 2628 CJ, The Netherlands [2] Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Vienna A-1090, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Gröblacher
authors.affiliation: Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Vienna A-1090, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Trubarov
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, Berlin 14195, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Prigge
authors.affiliation: Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Vienna A-1090, Austria.
authors.forename: G D
authors.initials: GD
authors.lastname: Cole
authors.affiliation: 1] Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Vienna A-1090, Austria [2] Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, Berlin 14195, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Aspelmeyer
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, Berlin 14195, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Eisert