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Title: Nonlinear terahertz response of HgTe/CdTe quantum wells

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4929754· OSTI ID:22489142
 [1]; ;  [2]
  1. School of Physics and Electronics, Hunan University, Changsha 410082 (China)
  2. School of Physics, University of Wollongong, Wollongong, New South Wales 2522 (Australia)

Without breaking the topological order, HgTe/CdTe quantum wells can have two types of bulk band structure: direct gap type (type I) and indirect gap type (type II). We report that the strong nonlinear optical responses exist in both types of bulk states under a moderate electric field in the terahertz regime. Interestingly, for the type II band structure, the third order conductivity changes sign when chemical potentials lies below 10 meV due to the significant response of the hole excitation close to the bottom of conduction band. Negative nonlinear conductivities suggest that HgTe/CdTe quantum wells can find application in the gain medium of a laser for terahertz radiation. The thermal influences on nonlinear optical responses of HgTe/CdTe quantum wells are also studied.

OSTI ID:
22489142
Journal Information:
Applied Physics Letters, Vol. 107, Issue 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English