A tunable terahertz (THz) narrowband absorber in view of bulk Dirac semimetal (BDS) is designed in this paper. The tunable terahertz absorber's basic unit comprises BDS, intermediate medium, and metal substrate. The BDS has good surface conductivity and the Fermi energy of that is flexible tunable, and the good surface conductivity might make controlled by Fermi energy. The absorption characteristics of the designed absorber are simulated by the finite integral time domain technique. The calculation results show that the designed absorber achieves ideal absorption in 139.97 μm, 163.52 μm, 247.76 μm bands, and the absorption rate is more than 0.96, which realizes ideal narrowband absorption and dynamic tuning. We find that the absorption peaks are flexible and adjustable by changing the Fermi energy of BDS, and the frequency adjustability of the absorber is analyzed. In addition, the effects of different structural parameters on the absorption efficiency and the absorption performance at different incident angles are studied. These results show that, compared with traditional metamaterials, Dirac semimetallic absorbing materials can tune the resonant frequency more effectively, even without reconstructing the structure, which has great application value in many fields, and provide a new reference for future research.

针对体狄拉克半金属（BDS），设计了一种可调谐的太赫兹（THz）窄带吸收器。可调太赫兹吸收器的基本单元包括BDS，中间介质和金属基底。BDS具有良好的表面电导率，并且其费米能量可灵活调节，并且良好的表面电导率可通过费米能量进行控制。通过有限积分时域技术模拟了设计的吸收体的吸收特性。计算结果表明，所设计的吸收器在139.97μm，163.52μm，247.76μm波段均达到理想吸收，吸收率大于0.96，实现了理想的窄带吸收和动态调谐。我们发现，通过改变BDS的费米能量，吸收峰是灵活且可调节的，并分析了吸收器的频率可调性。此外，研究了不同结构参数对不同入射角下的吸收效率和吸收性能的影响。这些结果表明，与传统的超材料相比，狄拉克半金属吸收材料即使不进行结构重构也可以更有效地调谐谐振频率，在许多领域具有重要的应用价值，并为今后的研究提供了新的参考。