Experimental Sensitivity Enhancement of a Quantum Rydberg Atom-Based RF Receiver with a Metamaterial GRIN Lens

TL;DR

This paper demonstrates that integrating a metamaterial GRIN lens with a Rydberg atom-based RF receiver significantly enhances its sensitivity across a wide frequency range, validated through experimental measurements.

Contribution

The study introduces a novel integration of a metamaterial GRIN lens with a quantum Rydberg RF receiver, achieving notable sensitivity improvements validated experimentally.

Findings

Enhanced EIT window with the lens

Reduced minimum detectable electric field

Improved measurement sensitivity over ultrawide bandwidth

Abstract

We experimentally demonstrate enhanced sensitivity of an atom-based Rydberg radio frequency (RF) receiver integrated with a gradient refractive index (GRIN) Luneburg-type metamaterial lens. By analyzing the electromagnetically induced transparency (EIT) effect in Cesium vapor, we compare receiver performance with and without the GRIN lens under a 2.2~GHz and a 3.6~GHz far-field excitation. Our measurements reveal a significant amplification of the EIT window when the lens is introduced, consistent with the theoretical prediction that the local E-field enhancement at the vapor cell reduces the minimum detectable electric field and improves the microwave electric field measurement sensitivity of the Rydberg atom-based RF receiver over an ultrawide bandwidth of the lens. This experimental validation demonstrates the potential of metamaterial-enhanced quantum RF sensing for a wide range of applications, such as electromagnetic compatibility (EMC) testing, quantum radar, and wireless communication.