Giant photon momentum locked THz emission in a centrosymmetric Dirac semimetal.

Autor: Cheng L; School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China.; State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China., Xiong Y; Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore., Kang L; Division of Advanced Materials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China., Gao Y; School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China., Chang Q; Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore., Chen M; Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore., Qi J; School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China.; State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China., Yang H; Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore., Liu Z; School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637371, Singapore., Song JCW; Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore., Chia EEM; Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Jazyk: angličtina
Zdroj: Science advances [Sci Adv] 2023 Jan 04; Vol. 9 (1), pp. eadd7856. Date of Electronic Publication: 2023 Jan 04.
DOI: 10.1126/sciadv.add7856
Abstrakt: Strong second-order optical nonlinearities often require broken material centrosymmetry, thereby limiting the type and quality of materials used for nonlinear optical devices. Here, we report a giant and highly tunable terahertz (THz) emission from thin polycrystalline films of the centrosymmetric Dirac semimetal PtSe 2 . Our PtSe 2 THz emission is turned on at oblique incidence and locked to the photon momentum of the incident pump beam. Notably, we find an emitted THz efficiency that is giant: It is two orders of magnitude larger than the standard THz-generating nonlinear crystal ZnTe and has values approaching that of the noncentrosymmetric topological material TaAs. Further, PtSe 2 THz emission displays THz sign and amplitude that is controlled by the incident pump polarization and helicity state even as optical absorption is only weakly polarization dependent and helicity independent. Our work demonstrates how photon drag can activate pronounced optical nonlinearities that are available even in centrosymmetric Dirac materials.
Databáze: MEDLINE