Ultrasensitive Anisotropic Room-Temperature Terahertz Photodetector Based on an Intrinsic Magnetic Topological Insulator MnBi2Te4

Cheng Guo; Zhiqingzi Chen; Xianbin Yu; Libo Zhang; Xueyan Wang; Xiaoshuang Chen; Lin Wang

doi:10.1021/acs.nanolett.2c02434

Ultrasensitive Anisotropic Room-Temperature Terahertz Photodetector Based on an Intrinsic Magnetic Topological Insulator MnBi₂Te₄

Nano Lett. 2022 Sep 28;22(18):7492-7498. doi: 10.1021/acs.nanolett.2c02434. Epub 2022 Sep 12.

Authors

Cheng Guo¹, Zhiqingzi Chen², Xianbin Yu^{1

3}, Libo Zhang⁴, Xueyan Wang⁵, Xiaoshuang Chen^{2

4}, Lin Wang^{1

2}

Affiliations

¹ Research Center for Intelligent Networks, Zhejiang Lab, Hangzhou 311121, China.
² State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai 200083, China.
³ College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
⁴ College of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
⁵ Department of Physics, Shanghai Normal University, 100 Guilin Rd, Shanghai 200234, China.

PMID: 36094834
DOI: 10.1021/acs.nanolett.2c02434

Abstract

Terahertz photodetectors based on emergent intrinsic magnetic topological insulators promise excellent performance in terms of highly sensitive, anisotropic and room-temperature ability benefiting from their extraordinary material properties. Here, we propose and conceive the response features of exfoliated MnBi₂Te₄ flakes as active materials for terahertz detectors. The MnBi₂Te₄-based photodetectors show the sensitivity rival with commercially available ones, and the noise equivalent power of 13 pW/Hz^0.5 under 0.275 THz at room-temperature led by the nonlinear Hall effect, allowing for the high-resolution terahertz imaging. In addition, a large anisotropy of polarization-dependent terahertz response is observed when the MnBi₂Te₄ device is tuned into different directions. More interestingly, we discover an unprecedented power-controlled reversal of terahertz response in the MnBi₂Te₄-graphene device. Our results provide feasibility of manipulating and exploiting the nontrivial topological phenomena of MnBi₂Te₄ under a high-frequency electromagnetic field, representing the first step toward device implementation of intrinsic magnetic topological insulators.

Keywords: MnBi2Te4; high sensitivity; intrinsic magnetic topological insulators; polarization sensitive; terahertz photodetector.