A scheme is proposed for a tunable broadband microwave absorber using a four-level Rydberg atom system with competition between electromagnetically induced transparency (EIT) and coherent population trapping (CPT). Two laser fields drive the Rydberg atoms from the ground state to a Rydberg state, forming a cascade-type EIT/CPT system. When a microwave (MW) field couples the Rydberg transition, a strong MW absorption peak appears. A narrow band MW absorber could be obtained via EIT, however, using CPT, the MW absorption spectrum can be significantly broadened and enhanced to have a bandwidth about ten times larger than that obtained with EIT and whose peak value can also be enhanced by a factor of ten, based on simulation.

中文翻译：

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基于相干阱的可调谐宽带微波吸收器

提出了一种使用四能级里德堡原子系统的可调宽带微波吸收器的方案，该方案在电磁感应透明性（EIT）和相干人口陷阱（CPT）之间具有竞争性。两个激光场将里德堡原子从基态驱动到里德堡态，从而形成级联EIT / CPT系统。当微波（MW）场耦合Rydberg跃迁时，出现一个很强的MW吸收峰。可以通过EIT获得窄带MW吸收器，但是，使用CPT可以显着拓宽和增强MW吸收光谱，使其带宽大约是EIT所获得的带宽的十倍，并且其峰值也可以提高一倍十个，基于模拟。