Piezo-orbital backaction force in a rare-earth doped crystal

TL;DR

This paper demonstrates a novel piezo-orbital backaction force in a rare-earth doped crystal, revealing how resonant atomic excitation induces a mechanical response through both conservative and dissipative optomechanical processes.

Contribution

It uncovers the piezo-orbital backaction mechanism in rare-earth doped crystals and distinguishes it from photothermal effects, advancing understanding of hybrid optomechanical interactions.

Findings

Identification of a piezo-orbital backaction force.

Distinction between conservative and dissipative processes.

Implications for rare-earth ion dephasing dynamics.

Abstract

We investigate a system composed of an ensemble of room temperature rare-earth ions embedded in a bulk crystal, intrinsically coupled to internal strain via their sensitivity to the surrounding crystal field. We evidence the generation of a mechanical response under resonant atomic excitation. We find this motion to be the sum of two fundamental, resonant optomechanical backaction processes: a conservative, piezo-orbital mechanism, resulting from the modification of the crystal field associated with the promotion of the ions to their excited state, and a dissipative, non-radiative photothermal process related to the phonons generated throughout the atomic population relaxation. Our work opens new research avenues in hybrid optomechanics, and highlights new interactions that may be key for understanding the dephasing dynamics of ultra-coherent rare-earth ions.