Enhancing the Instantaneous Bandwidth of Rydberg Microwave Sensors: A Proposed Scheme

Abstract

Rydberg atoms have emerged as a highly promising platform for microwave electric field sensing. Their practical deployment as next-generation sensors is fundamentally limited by the inherent trade-off between sensitivity and instantaneous bandwidth: enhancing instantaneous bandwidth while preserving high sensitivity remains a long-standing challenge in the field. Here we propose and experimentally demonstrate a novel scheme to overcome this limitation by introducing an auxiliary microwave field. This approach achieves a significant enhancement in instantaneous bandwidth while maintaining a high level sensitivity. Our experimental results demonstrate that an instantaneous bandwidth of 44.6$\,$MHz ($\pm$22.3$\,$MHz) is realized while achieving a sensitivity of 225.7$\,$nV$\,$cm$^{-1}\,$Hz$^{-1/2}$. This work provides a new pathway to simultaneously optimize the instantaneous bandwidth and sensitivity of Rydberg microwave sensors, facilitating their practical applications in radar and communications.