Dynamical Backaction Cooling with Free Electrons

TL;DR

This paper demonstrates a novel self-induced cooling mechanism for nanowires using a focused electron beam, achieving significant temperature reduction without electromagnetic mediation, with implications for nanoscale physics.

Contribution

It introduces the first experimental realization of a non-electromagnetic, self-induced cooling process for mechanical motion, expanding cooling techniques beyond laser-based methods.

Findings

Achieved 50-fold reduction in nanowire motional temperature.

Demonstrated cooling via focused electron beam without electromagnetic fields.

Generalized the mechanism to other delayed and confined interactions.

Abstract

The ability to cool single ions, atomic ensembles, and more recently macroscopic degrees of freedom down to the quantum groundstate has generated considerable progress and perspectives in Basic and Technological Science. These major advances have been essentially obtained by coupling mechanical motion to a resonant electromagnetic degree of freedom in what is generally known as laser cooling. In this work, we experimentally demonstrate the first self-induced coherent cooling mechanism that is not mediated by the electromagnetic field. Using a focused electron beam, we report a 50-fold reduction of the motional temperature of a nanowire. Our result primarily relies on the sub-nanometer confinement of the electron beam and generalizes to any delayed and topologically confined interaction, with important consequences for near-field microscopy and fundamental nanoscale dissipation mechanisms.