Quantum Superposition of Massive Objects and Collapse Models

TL;DR

This paper explores the experimental requirements and limitations for testing collapse models using quantum superpositions of massive objects, focusing on optomechanical systems and environmental decoherence effects.

Contribution

It presents a general framework for testing collapse models with massive superpositions and analyzes practical experimental constraints in cavity optomechanics setups.

Findings

Decoherence from blackbody radiation and environmental scattering limits superposition coherence.

Proposes a protocol involving wave function expansion and double slit measurement.

Identifies key experimental challenges in levitating dielectric nanospheres.

Abstract

We analyze the requirements to test some of the most paradigmatic collapse models with a protocol that prepares quantum superpositions of massive objects. This consists of coherently expanding the wave function of a ground-state-cooled mechanical resonator, performing a squared position measurement that acts as a double slit, and observing interference after further evolution. The analysis is performed in a general framework and takes into account only unavoidable sources of decoherence: blackbody radiation and scattering of environmental particles. We also discuss the limitations imposed by the experimental implementation of this protocol using cavity quantum optomechanics with levitating dielectric nanospheres.