Modification of phonon processes in nanostructured rare-earth-ion-doped crystals

TL;DR

Nano-structuring rare-earth-ion-doped crystals alters phonon interactions, enhancing spectral hole-burning and coherence, which benefits quantum memory and spectrum analysis applications.

Contribution

This paper introduces phonon engineering via nano-structuring to improve spectral properties of rare-earth-ion-doped crystals for quantum technologies.

Findings

Nano-structuring modifies phonon density of states.

Simulations show enhanced spectral hole-burning potential.

Phononic crystals enable spectral control in quantum memory materials.

Abstract

Nano-structuring impurity-doped crystals affects the phonon density of states and thereby modifies the atomic dynamics induced by interaction with phonons. We propose the use of nano-structured materials in the form of powders or phononic bandgap crystals to enable or improve persistent spectral hole-burning and coherence for inhomogeneously broadened absorption lines in rare-earth-ion-doped crystals. This is crucial for applications such as ultra-precise radio-frequency spectrum analyzers and optical quantum memories. As an example, we discuss how phonon engineering can enable spectral hole burning in erbium-doped materials operating in the convenient telecommunication band, and present simulations for density of states of nano-sized powders and phononic crystals for the case of Y2SiO5, a widely-used material in current quantum memory research.