Mechanical tunability of an ultra-narrow spectral feature with uniaxial stress

TL;DR

This paper demonstrates that applying uniaxial stress to rare-earth doped crystals can controllably shift narrow spectral features, enhancing their utility in precision applications like quantum information processing.

Contribution

It introduces a method to tune spectral holes in Eu³⁺:Y₂SiO₅ crystals using uniaxial stress, revealing site- and axis-dependent sensitivities.

Findings

Uniaxial stress can shift spectral holes beyond their width.

Sensitivity varies with crystal site and stress axis.

Controlled spectral tuning is achievable with mechanical stress.

Abstract

Rare-earth doped crystals have numerous applications ranging from frequency metrology to quantum information processing. To fully benefit from their exceptional coherence properties, the effect of mechanical strain on the energy levels of the dopants - whether it is a resource or perturbation - needs to be considered. We demonstrate that by applying uniaxial stress to a rare-earth doped crystal containing a spectral hole, we can shift the hole by a controlled amount that is larger than the width of the hole. We deduce the sensitivity of $\rm Eu^{3+}$ ions in an $\rm Y_2SiO_5$ matrix as a function of crystal site and the crystalline axis along which the stress is applied.