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

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.

v1: Initial draft, comments are welcome. v2: introduction is modified, robustness of this scheme against measurement imprecision and tuning of the parameters is added. v3: close to published version

References in corpus (7)

• A Spin Entanglement Witness for Quantum Gravity
• Gravitationally-induced entanglement between two massive particles is sufficient evidence of quantum effects in gravity
• Sensitivity and Performance of the Advanced LIGO Detectors in the Third Observing Run
• Ideal negative measurements in quantum walks disprove theories based on classical trajectories
• Testing collapse models with levitated nanoparticles: the detection challenge
• Wigner's form of the Leggett-Garg inequality, No-Signalling in Time, and Unsharp Measurements
• Leggett-Garg violations for continuous variable systems with gaussian states

Cited by in corpus (4)

• Limit on spatial quantum superpositions with massive objects due to phonons
• Violation of the two-time Leggett-Garg inequalities for a harmonic oscillator
• Newton's laws of motion generating gravity-mediated entanglement
• Classifying Measurement Incompatibility under Classical Pre- and Post-Processing Operations