Low-Power Polarization Sensitive Terahertz Photodetection Driven by Ternary Type-II Weyl Semimetal NbIrTe₄

Abstract

Type-II Weyl semimetals have emerged as ideal candidate materials for terahertz (THz) photodetection due to the high mobility, intrinsic anisotropy and topological band structure. Herein, type-II Weyl semimetal NbIrTe4 based THz photodetectors (PDs) coupled with bow-tie antenna structure were successfully explored. Driven by the intrinsic Weyl fermions, an ultrahigh sensitivity of 3.95 pW/Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{{\textbf {1}/{2}}}$ </tex-math></inline-formula> and a fast photoresponse speed of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.46 \mu \text{s}$ </tex-math></inline-formula> are achieved in an unbiased mode. Furthermore, the anisotropic THz photoresponse with a dichroic ratio of 14.1 and the high-resolution transmission THz imaging are demonstrated. These results pave the way for utilizing the unique topological effects of type-II Weyl semimetals in low-power polarization sensitive THz applications.