Creating Single Collective Atomic Excitations via Spontaneous Raman Emission in Inhomogeneously Broadened Systems : Beyond the Adiabatic Approximation

TL;DR

This paper investigates how near-resonance excitation affects the creation of collective atomic excitations via spontaneous Raman emission in inhomogeneously broadened systems, extending beyond the traditional adiabatic approximation.

Contribution

It provides a theoretical analysis of near-resonance effects on collective excitations in inhomogeneously broadened ensembles, relevant for hot gases and solid-state quantum systems.

Findings

Near-resonance excitation modifies collective properties of atomic excitations.

Inhomogeneous broadening impacts the efficiency of Raman-based quantum protocols.

Results are applicable to hot atomic gases and solid-state quantum devices.

Abstract

The creation of single collective excitations in atomic ensembles via spontaneous Raman emission plays a key role in several quantum communication protocols, starting with the seminal DLCZ protocol [L.-M.Duan, M.D. Lukin, J.I. Cirac, and P. Zoller, Nature {\bf 414}, 413 (2001).] This process is usually analyzed theoretically under the assumptions that the write laser pulse inducing the Raman transition is far off-resonance, and that the atomic ensemble is only homogeneously broadened. Here we study the impact of near-resonance excitation for inhomogeneously broadened ensembles on the collective character of the created atomic excitation. Our results are particularly relevant for experiments with hot atomic gases and for potential future solid-state implementations.