Stimulated generation of indistinguishable single photons from a quantum ladder system

TL;DR

This paper introduces a scheme using semiconductor quantum dots for generating highly indistinguishable single photons with low multi-photon errors and programmable polarization, enhancing quantum communication applications.

Contribution

The paper presents a novel two-photon excitation and stimulation scheme that improves photon indistinguishability and brightness without polarization filtering.

Findings

Significant reduction in multi-photon errors.

High photon indistinguishability achieved.

Polarization of photons is deterministically controlled.

Abstract

We propose a scheme for the generation of highly indistinguishable single photons using semiconductor quantum dots and demonstrate its performance and potential. The scheme is based on the resonant two-photon excitation of the biexciton followed by stimulation of the biexciton to selectively prepare an exciton. Quantum-optical simulations and experiments are in good agreement and show that the scheme provides significant advantages over previously demonstrated excitation methods. The two-photon excitation of the biexciton suppresses re-excitation and enables ultra-low multi-photon errors, while the precisely timed stimulation pulse results in very low timing jitter of the photons, and consequently, high indistinguishability. Since both control laser fields are detuned from the emission energy, the scheme does not require polarization filtering, facilitating high brightness approaching unity. Moreover, the polarization of the emitted single photons is controlled by the stimulation laser field, such that the polarization of the quantum light is deterministically programmable.