A tunable triple-band absorber based on bulk-Dirac-semimetal (BDS) metasurface is proposed in the terahertz (THz) range. The design is comprised of a BDS film with a pattern of dual ring slots and a dielectric layer stacked on a fully reflective gold ground. And the electric or magnetic resonances result in the incident plane waves at different frequencies to be effectively absorbed by the BDS film, which leads to the high absorption at 1.56 THz, 3.28 THz, and 3.95 THz resonant frequencies. The tunability of the resonant frequencies depends on various Fermi levels. Moreover, the physical mechanisms of the absorber with good stability over wide incident angles and polarization insensitivity are expounded. The proposed BDS-based absorber has great potentials in sensors, thermal emitters, and energy harvesting, etc.

中文翻译：

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基于体-狄拉克-半金属超表面的可调三频太赫兹吸收器

在太赫兹 (THz) 范围内提出了一种基于体狄拉克半金属 (BDS) 超表面的可调三频吸收器。该设计由带有双环槽图案的 BDS 薄膜和堆叠在全反射金地面上的介电层组成。并且电或磁共振导致不同频率的入射平面波被BDS薄膜有效吸收，从而导致在1.56 THz、3.28 THz和3.95 THz谐振频率处的高吸收。谐振频率的可调性取决于各种费米能级。此外，阐述了在宽入射角下具有良好稳定性和偏振不敏感性的吸收体的物理机制。所提出的基于 BDS 的吸收器在传感器、热发射器和能量收集等方面具有巨大的潜力。