On-chip indistinguishable photons using III-V nanowire/SiN hybrid integration

Edith Yeung, David B. Northeast, Jeongwan Jin, Patrick Laferrière, Marek Korkusinski, Philip J. Poole, Robin L. Williams, and Dan Dalacu

Phys. Rev. B 108, 195417 – Published 13 November 2023

Abstract

We demonstrate on-chip generation of indistinguishable photons based on a nanowire quantum dot. From a growth substrate containing arrays of positioned-controlled single-dot nanowires, we select a single nanowire which is placed on a SiN waveguide fabricated on a Si-based chip. Coupling of the quantum dot emission to the SiN waveguide is via the evanescent mode in the tapered nanowire. Postselected two-photon interference visibilities using continuous-wave excitation above band and into a $p$ shell of the dot were 100% consistent with a single-photon source having negligible multiphoton emission probability. Visibilities over the entire photon wave packet, measured using pulsed excitation, were reduced by a factor of 5 when exciting quasiresonantly and by a factor of 10 for above-band excitation. The role of excitation timing jitter, spectral diffusion, and pure dephasing in limiting visibilities over the temporal extent of the photon is investigated using additional measurements of the coherence and linewidth of the emitted photons.