All-metallic magnetic Purcell enhancement in a thermally stable room-temperature maser
摘要
Enhancing the spontaneous and stimulated emission rates of magnetic quantum emitters through the Purcell effect is essential for designing high-performance quantum devices based on high quality factor and small mode volume. At room temperature, structures constructed using high-index dielectric materials have been favored due to their ability to effectively confine electromagnetic fields. However, these dielectric resonators are plagued by an inherent sensitivity to thermal variations, which are unavoidable during the optical excitation or readout of the quantum states. Here, we propose to solve this issue with a dielectric-free, all-metallic toroidal split-ring resonator cluster of subwavelength size (≤λm/17), which exhibits a fundamental magnetic mode at approximately 1.45 GHz (λm ~ 207 mm) and a remarkably low mode volume (