Phonon Interferometry for Measuring Quantum Decoherence

TL;DR

This paper proposes a robust scheme to entangle two mechanical resonators in superposition states, enabling the study of quantum decoherence in macroscopic objects through optomechanical systems.

Contribution

It introduces a general entanglement scheme for mechanical resonators that is resilient to experimental imperfections, advancing the investigation of quantum collapse models.

Findings

Scheme is resilient to incomplete pre-cooling

Effective despite faulty postselection

Applicable to various optomechanical systems

Abstract

Experimental observation of the decoherence of macroscopic objects is of fundamental importance to the study of quantum collapse models and the quantum to classical transition. Optomechanics is a promising field for the study of such models because of its fine control and readout of mechanical motion. Nevertheless, it is challenging to monitor a mechanical superposition state for long enough to investigate this transition. We present a scheme for entangling two mechanical resonators in spatial superposition states such that all quantum information is stored in the mechanical resonators. The scheme is general and applies to any optomechanical system with multiple mechanical modes. By analytic and numeric modeling, we show that the scheme is resilient to experimental imperfections such as incomplete pre-cooling, faulty postselection and inefficient optomechanical coupling. This proposed procedure overcomes limitations of previously proposed schemes that have so far hindered the study of macroscopic quantum dynamics.