Photophysics of Intrinsic Single-Photon Emitters in Silicon Nitride at Low Temperatures

TL;DR

This study investigates the fundamental photophysical properties of intrinsic single-photon emitters in silicon nitride across a temperature range, providing insights into their linewidths and broadening mechanisms relevant for quantum photonics.

Contribution

It offers new measurements of optical transition properties and broadening mechanisms of silicon nitride emitters, advancing their potential for quantum applications.

Findings

Spectral diffusion dominates linewidth broadening at 4.2K

Zero-phonon lines are homogeneously broadened with instrument-limited linewidths

Temperature-dependent broadening mechanisms are characterized

Abstract

A robust process for fabricating intrinsic single-photon emitters in silicon nitride has been recently established. These emitters show promise for quantum applications due to room-temperature operation and monolithic integration with the technologically mature silicon nitride photonics platform. Here, the fundamental photophysical properties of these emitters are probed through measurements of optical transition wavelengths, linewidths, and photon antibunching as a function of temperature from 4.2K to 300K. Important insight into the potential for lifetime-limited linewidths is provided through measurements of inhomogeneous and temperature-dependent homogeneous broadening of the zero-phonon lines. At 4.2K, spectral diffusion was found to be the main broadening mechanism, while time-resolved spectroscopy measurements revealed homogeneously broadened zero-phonon lines with instrument-limited linewidths.