Quantum-Limited Atomic Receiver in the Electrically Small Regime

TL;DR

This paper demonstrates a quantum sensor based on thermal Rydberg atoms capable of receiving electromagnetic data in the electrically small regime, surpassing classical antenna limitations with quantum-limited data capacity.

Contribution

It introduces the standard quantum limit for data capacity and experimentally achieves quantum-limited data reception in extremely small sensing volumes.

Findings

Quantum-limited data reception observed from 10 kHz to 30 MHz bandwidths.

Sensing volume over 10^7 times smaller than the wavelength cube.

Provides an alternative to classical antennas in electrically small regimes.

Abstract

We use a quantum sensor based on thermal Rydberg atoms to receive data encoded in electromagnetic fields in the extreme electrically small regime, with a sensing volume over $10^7$ times smaller than the cube of the electric field wavelength. We introduce the standard quantum limit for data capacity, and experimentally observe quantum-limited data reception for bandwidths from 10~kHz up to 30~MHz. In doing this, we provide a useful alternative to classical communication antennas, which become increasingly ineffective when the size of the antenna is significantly smaller than the wavelength of the electromagnetic field.