Dispersion Outperforms Absorption: EIT-Enhanced Atomic Localization and Gradient Sensing with Super-Gaussian Beams

TL;DR

This paper theoretically compares absorption and EIT-based atomic gradient sensing, demonstrating EIT's superior sensitivity and localization capabilities due to its steep dispersion response, with implications for advanced quantum metrology.

Contribution

It provides the first comprehensive theoretical comparison showing EIT's advantages over absorption in atomic gradient sensing under optimized conditions.

Findings

EIT outperforms absorption in gradient sensitivity by up to an order of magnitude.

Both methods achieve sub-diffraction resolution around 0.3-0.4 lambda.

EIT offers sharper edge contrast and higher localization accuracy.

Abstract

This work presents a comprehensive theoretical comparison between absorption-based and electromagnetically induced transparency (EIT)-based atomic gradient sensing in a four-level tripod system. Both methods were evaluated under identical and optimized physical conditions to ensure a fair and unbiased comparison. The analysis demonstrates that EIT, driven by its steep dispersion response, consistently outperforms conventional absorption detection across a wide range of super-Gaussian beam profiles. Under optimal detuning, EIT achieved up to an order-of-magnitude enhancement in gradient sensitivity and maintained a twofold advantage even under identical detuning. Both approaches reached sub-diffraction spatial resolution in the range of 0.29lambda-0.40lambda, with EIT exhibiting sharper edge contrast and higher localization accuracy. These results confirm EIT as a fundamentally superior approach for precision atomic gradient sensing and sub-wavelength localization, offering clear guidance for the design of next-generation optical and quantum metrology systems.