Generation of "triggered single photons" from a coherently-pumped quantum dot

TL;DR

This paper presents a method to generate highly efficient, indistinguishable single photons from a quantum dot-cavity system using cavity-assisted adiabatic Raman passage, overcoming previous limitations of incoherent pumping.

Contribution

The authors introduce a cavity-assisted adiabatic Raman passage technique to produce on-demand single photons with high efficiency and indistinguishability from a solid-state quantum dot system.

Findings

Achieved 100% efficiency in single-photon generation.

Demonstrated >90% indistinguishability of emitted photons.

Utilized current experimental parameters for practical implementation.

Abstract

A deterministic "on demand" source of single photons is a basic building block for linear quantum computation \cite{linear}, quantum cryptography \cite{crypto}, quantum teleportation \cite{teleport}, and quantum networks \cite{network}. In all these applications, quantum interference between two single-photon pulses on a symmetric beam splitter has been exploited \cite{review}, which imposes stringent requirement for the implemented single photons to be indistinguishable in all degrees of freedom, including their frequencies, spectral widths, pulse shapes, and polarizations. To generate single photons one requires a pumping mechanism to excite a "two-level emitter" and an efficient channeling of the subsequently emitted photons. The efficiency of the source can be enhanced by coupling the emitter to the waveguide \cite{manga} or a microcavity mode \cite{cklaw}. However, hitherto the solid-state single photon sources realized by using a quantum dot coupled with a microcavity rely on incoherent pumping of excitons, which leads to problems with timing jitter \cite{kiraz}, leading to a trade off between efficiency and indistinguishability. Here we introduce a means to realize a highly efficient solid state source of indistinguishable single photons using cavity-assisted adiabatic Raman passage in a single quantum dot - cavity system. We demonstrate pulse-triggered single photons with 100% efficiency and $>90$% indistinguishability using currently available experimental parameters.