Correlated random walks caused by dynamical wavefunction collapse

Area of Science:

• Quantum Mechanics
• Foundations of Physics
• Experimental Physics

Background:

• Wavefunction collapse models offer a dynamical resolution to the quantum measurement problem by modifying Schrödinger's equation.
• These models predict a generic consequence: a minute random diffusive motion for particles.
• The Continuous Spontaneous Localization (CSL) model is a prominent collapse model with significant theoretical development.

Purpose of the Study:

• To investigate the correlated diffusive motion of particles within the CSL model.
• To propose a feasible experimental test for detecting these correlated diffusions.
• To establish a method for experimentally bounding the CSL length scale.

Main Methods:

• Theoretical analysis of the CSL model to demonstrate positive correlation in particle diffusions.
• Proposal of an experiment involving simultaneous release and measurement of displacements of nearby free nanoparticles from traps.
• Identification of experimental conditions (low temperature and pressure) required to isolate collapse effects from environmental noise.

Main Results:

• Demonstrated that the CSL model predicts positively correlated random diffusions for sufficiently nearby particles.
• The proposed experiment can be conducted with current technologies for a significant portion of the CSL model's parameter space.
• The correlated diffusion effect diminishes as particle separation exceeds the CSL length scale.

Conclusions:

• The correlated diffusion of nearby particles is a unique signature of the CSL model.
• The proposed experiment provides a viable method for testing the CSL model and bounding its characteristic length scale.
• This research bridges theoretical predictions of collapse models with practical experimental verification.