Mass-Independent Scheme to Test the Quantumness of a Massive Object

TL;DR

This paper proposes a mass-independent method to demonstrate the nonclassical nature of large masses using modified quantum tests, enabling easier experimental verification across a wide range of systems.

Contribution

It introduces a novel approach that allows testing quantum violations for any mass and frequency without precise tuning, simplifying experimental efforts.

Findings

Mass-independent violation of macrorealism demonstrated

Quantum violations detectable with coarse measurements

Applicable to systems from atomic ions to macroscopic mirrors

Abstract

The search for empirical schemes to evidence the nonclassicality of large masses is a central quest of current research. However, practical schemes to witness the irreducible quantumness of an arbitrarily large mass are still lacking. To this end, we incorporate crucial modifications to the standard tools for probing the quantum violation of the pivotal classical notion of macrorealism (MR): while usual tests use the same measurement arrangement at successive times, here we use two different measurement arrangements. This yields a striking result: a mass-independent violation of MR is possible for harmonic oscillator systems. In fact, our adaptation enables probing quantum violations for literally any mass, momentum, and frequency. Moreover, coarse-grained position measurements at an accuracy much worse than the standard quantum limit, as well as knowing the relevant parameters only to this precision, without requiring them to be tuned, suffice for our proposal. These should drastically simplify the experimental effort in testing the nonclassicality of massive objects ranging from atomic ions to macroscopic mirrors in LIGO.