arXiv subjects

Ruffin Evans

Publications and source records attributed to Ruffin Evans.

2 recordsLinked to original sources

arXiv2020

Cavity-Enhanced Photon Emission from a Single Germanium-Vacancy Center in a Diamond Membrane

The nitrogen-vacancy center in diamond has been explored extensively as a light-matter interface for quantum information applications, however it is limited by low coherent photon emission and spectral instability. Here, we present a promising interface based on an alternate defect with superior optical properties (the germanium-vacancy) coupled to a finesse $\approx11{,}000$ fiber cavity, resulting in a $31^{+11}_{-15}$-fold increase in the spectral density of emission. This work sets the stage for cryogenic experiments, where we predict a measurable increase in the spontaneous emission rate.

quant-ph↗

arXiv2011

On the experimental violation of Mermin's inequality with imperfect measurements

We investigate theoretically the feasibility of an experimental test of the Bell-type inequality derived by Mermin for correlated spins larger than 1/2. Using the Schwinger representation, we link the output fields of two two-mode squeezers in order to create correlated effective spins between two observers. Spin measurements will be performed by photon-number-resolved photodetection, which has recently come of age. We examine the effect of nonideal detection quantum efficiency---and any other optical loss---on the violation margin of Mermin's inequality. We find that experimental violation is well accessible for spins larger than 1 for quantum efficiencies compatible with the current state of the art.

quant-ph↗