A Nanoscale Experiment Measuring Gravity's Role in Breaking the Unitarity of Quantum Dynamics

Abstract

Modern, state of the art nanomechanical devices are capable of creating spatial superpositions that are massive enough to begin to experimentally access the quantum to classical crossover, and thus force us to consider the possible ways in which the usual quantum dynamics may be affected. One recent theoretical proposal describes the crossover from unitary quantum mechanics to classical dynamics as a form of spontaneous symmetry breaking. Here, we propose a specific experimental setup capable of identifying the source of unitarity breaking in such a mechanism. The experiment is aimed specifically at clarifying the role played by gravity, and distinguishes the resulting dynamics from that suggested by alternative scenarios for the quantum to classical crossover. We give both a theoretical description of the expected dynamics, and a discussion of the involved experimental parameter values and the proposed experimental protocol.

11 pages, 5 figures; final version

References in corpus (11)

• Cooling a nanomechanical resonator with quantum back-action
• Millikelvin cooling of an optically trapped microsphere in vacuum
• Gravitation and quantummechanical localization of macroobjects
• Carbon nanotubes as ultra-high quality factor mechanical resonators
• Quenching Spin Decoherence in Diamond through Spin Bath Polarization
• Creating and Verifying a Quantum Superposition in a Micro-optomechanical System
• Entanglement of macroscopic test masses and the Standard Quantum Limit in laser interferometry
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• Damping and decoherence of a nanomechanical resonator due to a few two level systems
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Cited by in corpus (14)

• Macroscopic Quantum Mechanics: Theory and Experimental Concepts of Optomechanics
• Single-photon cavity optomechanics mediated by a quantum two-level system
• Upper bounds on spontaneous wave-function collapse models using millikelvin-cooled nanocantilevers
• Macroscopic Quantum Mechanics in a Classical Spacetime
• Single-Spin Magnetomechanics with Levitated Micromagnets
• Probing macroscopic realism via Ramsey correlations measurements
• Theory of Quantum Acoustomagnonics and Acoustomechanics with a Micromagnet
• Feedback-enhanced parametric squeezing of mechanical motion
• Decoherence of a qubit due to a quantum fluctuator or to a classical telegraph noise
• Programmable Quantum Processors based on Spin Qubits with Mechanically-Mediated Interactions and Transport
• Quantum state reduction of general initial states through spontaneous unitarity violation
• Colored noise driven unitarity violation causing dynamical quantum state reduction
• Phase transitions as a manifestation of spontaneous unitarity violation
• Continuous spontaneous localization as the white-noise limit of spontaneous unitarity violation