Cherenkov terahertz radiation from Dirac semimetals surface plasmon polaritons excited by an electron beam<xref rid="cpb_29_3_034101fn1" ref-type="fn">*</xref><fn id="cpb_29_3_034101fn1"><label>*</label><p>Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0701000), the National Key Scientific Instrument and Equipment Development of China (Grant No. 2018YFF01013001), and the National Natural Science Foundation of China (Grant Nos. 61701084 and 61505022).</p></fn>

Cherenkov terahertz radiation from Dirac semimetals surface plasmon polaritons excited by an electron beam**

Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0701000), the National Key Scientific Instrument and Equipment Development of China (Grant No. 2018YFF01013001), and the National Natural Science Foundation of China (Grant Nos. 61701084 and 61505022).

Zhao Tao, Wu Zhenhua^†

(a) Schematic diagram of an electron bunch moving on top of a BDS film deposited on a dielectric substrate with a buffer layer. (b) The dispersion curves. The inset shows the Fourier spectra of the radiation intensity. The contour map of the electric field intensity E_z in the y–z plane at the frequencies of (c) 7.68 THz and (d) 9.44 THz. The thickness of the buffer layer h was 2 μm, and the permittivity of the buffer layer was 2.25. The other parameters were the same as those used in Fig. 2.