SUPER excitation of quantum emitters is a multi-photon process

TL;DR

This paper presents a fully quantized model of the SUPER excitation scheme, revealing it as a multi-photon process that involves complex energy exchange, offering new insights into quantum emitter excitation mechanisms.

Contribution

It introduces a novel quantum model demonstrating that SUPER excitation is a multi-photon process, providing a new physical interpretation of the scheme.

Findings

SUPER is a multi-photon process involving photon exchange between modes

The model reveals a non-linear interaction between emitters and field modes

Provides an unexpected physical understanding of the excitation mechanism

Abstract

The swing-up of quantum emitter population (SUPER) scheme allows to populate the excited state of a quantum emitter with near-unity fidelity using two red-detuned laser pulses. Its off-resonant, yet fully coherent nature has attracted significant interest in quantum photonics as a valuable tool for preparing single-photon sources in their excited state on demand, while simultaneously ensuring straightforward spectral filtering of the laser. However, the physical understanding of this mechanism in terms of energy exchange between the electromagnetic field and the emitter is still lacking. Here, we present a fully quantized model of the swing-up excitation and demonstrate that it is in fact a multi-photon process, where one of the modes loses two or more photons while the other gains at least one. Our findings provide an unexpected physical interpretation of the SUPER scheme and unveil a new non-linear interaction between single emitters and multiple field modes.