Sensitivity of electromagnetically induced transparency to light-mediated interactions

TL;DR

This paper models how light-mediated interactions in cold atomic ensembles affect electromagnetically induced transparency (EIT), revealing density-dependent narrowing of transparency and implications for quantum memory efficiency.

Contribution

It introduces a microscopic model accounting for long-range and near-field interactions in EIT, highlighting their impact on transparency and quantum memory performance.

Findings

Light-mediated interactions narrow EIT transparency window at higher densities.

Near-field effects influence atomic population transfer in STIRAP.

Standard STIRAP-based quantum memories may have limited efficiency due to these interactions.

Abstract

Here we present a microscopic model that describes the Electromagnetically Induced Transparency (EIT) phenomenon in the multiple scattering regime. We consider an ensemble of cold three-level atoms, in a $\Lambda$ configuration, scattering a probe and a control field to the vacuum modes of the electromagnetic field. By first considering a scalar description of the scattering, we show that the light-mediated long-range interactions that emerge between the dipoles narrow the EIT transparency window for increasing densities and sample sizes. For a vectorial description, we demonstrate that near-field interacting terms can critically affect the atomic population transfer in the Stimulated Raman Adiabatic Passage (STIRAP). This result points out that standard STIRAP-based quantum memories in cold atomic ensembles would not reach high enough efficiencies for quantum information processing applications even in dilute regimes.