# Collapse-induced Orientational Localization of Rigid Rotors

## TL;DR

This paper derives a master equation for the collapse-induced decoherence of rigid rotors under CSL, showing how it causes orientational localization and diffusion, with measurable effects on levitated nanorotors.

## Contribution

It introduces a detailed model of how CSL affects the rotational degrees of freedom of anisotropic particles, linking theoretical predictions to experimental observables.

## Key findings

- Collapse induces orientational decoherence and diffusion in rigid rotors.
- Heating rates depend differently on CSL parameters, enabling parameter estimation.
- The model applies to levitated nanorotors, suggesting experimental tests.

## Abstract

We show how the ro-translational motion of anisotropic particles is affected by the model of Continuous Spontaneous Localization (CSL), the most prominent hypothetical modification of the Schr\"odinger equation restoring realism on the macroscale. We derive the master equation describing collapse-induced spatio-orientational decoherence, and demonstrate how it leads to linear- and angular-momentum diffusion. Since the associated heating rates scale differently with the CSL parameters, the latter can be determined individually by measuring the random motion of a single levitated nanorotor.