2025/12/18 by Baltisberger, Timon L., Salusti, Francesco, Hogg, Mark R. +7
Materials Science · Computer Science · Physics and Astronomy · #Diamond and Carbon-based Materials Research #Quantum Information and Cryptography #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2512.16617
Decay of a four-level diamond scheme via a cascade is a potential source of entangled photon pairs. A solid-state implementation is the biexciton cascade in a semiconductor quantum dot. While high entanglement fidelities have been demonstrated, the two photons, XX and X, are temporally correlated, typically resulting in poor photon coherence. Here, we demonstrate a high two-photon interference visibility (a measure of the photon coherence) for both XX (V=94±2%) and X (V=82±6%) photons. This is achieved by Purcell-enhancing the biexciton transition in a low-noise device. We find that the photon coherence follows the well-known quantum optics result upon tuning the XX:X lifetime ratio over two orders of magnitude.