Title: A warm Rydberg atom-based quadrature amplitude-modulated receiver

Abstract: Rydberg atoms exhibit remarkable sensitivity to electromagnetic fields, making them promising candidates for revolutionizing field sensors. Unlike conventional antennas, they neither disturb the measured field nor necessitate intricate calibration procedures. In this study, we propose a protocol for signal reception near the 2.4 GHz Wi-Fi frequency band, harnessing the capabilities of warm Rydberg atoms. Our focus lies on exploring various quadrature amplitude modulations and transmission frequencies through heterodyne detection. We offer a comprehensive characterization of our setup, encompassing the atomic response frequency range and attainable electric field amplitudes. Additionally, we delve into analyzing communication errors using Voronoi diagrams, along with evaluating the communication channel capacity across different modulation schemes. Our findings not only lay the groundwork for future wireless communication applications, but also present opportunities to refine protocols in classical communication and field sensing domains.