Topological materials as promising candidates for tuneable helicity-dependent terahertz emitters

Conference item

Topological materials have rapidly gained interest as contenders for development of coherent, controllable terahertz emitters. Possessing Weyl nodes either at the surface or within the bulk, they host spin-polarised, helicity-dependent currents that offer possibility to control the emitted THz pulse by changing the polarization of the optical pulses generating the radiation. Here, we show that upon near-infrared excitation at oblique incidence, multi-cycle pulses are generated with a narrow bandwidth of ∼0.4 THz for cadmium arsenide bulk crystals and nanowire ensembles. Both the bandwidth and peak emission frequency of the generated THz radiation can be tuned by respectively varying the photon helicity and angle of incidence of the photoexcitation light.

Authors: Boland, JL; Damry, DA; Xia, CQ; Saboon, Y; Mannan, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Society of Photo-optical Instrumentation Engineers
• Host title: Proceedings of SPIE: Terahertz Emitters, Receivers, and Applications XIV
• Volume: 12683
• Article number: 1268302
• Publication date: 2023-10-04
• Acceptance date: 2023-09-01
• Event title: SPIE Optical Engineering + Applications 2023
• Event location: San Diego, California, United States
• Event website: https://spie.org/conferences-and-exhibitions/optics-and-photonics/program/conferences/optical-engineering--applications
• Event start date: 2023-08-21
• Event end date: 2023-08-22
• DOI: 10.1117/12.2681745
• EISSN: 1996-756X
• ISSN: 0277-786X
• EISBN: 9781510665811
• ISBN: 9781510665804
• Language: English
• Keywords: polarization; nanowires; photon polarization; crystals; terahertz spectroscopy; terahertz radiation