Indistinguishability of photons from cavity-enhanced spontaneous two-photon emission in quantum dots

Determine the indistinguishability of photons produced via cavity-enhanced spontaneous two-photon emission from the biexciton state of a semiconductor quantum dot, thereby characterizing whether such photons are suitable for high-visibility two-photon interference and networking tasks such as entanglement swapping.

Background

Semiconductor quantum dots can generate entangled photon pairs either through the biexciton cascade or by interfering independently emitted photons. A recently explored route uses cavity-enhanced spontaneous two-photon emission from the biexciton state, which can produce spectrally matched entangled pairs.

For quantum networking applications, photon indistinguishability is critical because it underpins high-fidelity two-photon interference and entanglement swapping. While cavity-enhanced spontaneous two-photon emission is promising, its photon indistinguishability has not yet been evaluated, leaving a key performance metric unknown.