Damping and decoherence of a nanomechanical resonator due to a few two level systems

TL;DR

This paper models a nanomechanical resonator interacting with a small number of damped two-level systems, revealing amplitude-dependent damping and weak decoherence dependence on superposition size.

Contribution

It introduces a quantum model for a resonator coupled to few TLS's, highlighting unique damping and decoherence behaviors distinct from traditional bath models.

Findings

Damping depends on oscillation amplitude.

Decoherence weakly depends on superposition size.

Model differs from standard oscillator bath interactions.

Abstract

We consider a quantum model of a nanomechanical flexing beam resonator interacting with a bath comprising a few damped tunneling two level systems (TLS's). In contrast with a resonator interacting bilinearly with an ohmic free oscillator bath (modeling clamping loss, for example), the mechanical resonator damping is amplitude dependent, while the decoherence of quantum superpositions of mechanical position states depends only weakly on their spatial separation.