Spectroscopy of temperature-driven single valley Dirac fermions in HgTe/CdHgTe quantum wells

A. M. Kadykov , Sergey S. Krishtopenko (1) , Benoit Jouault (1) , W. Desrat (1) , M. Marcinkiewicz (1) , S. Ruffenach (1) , C. Consejo (1) , J. Torres (2, 3) , S. V. Morozov (4) , V. I. Gavrilenko (4) , N. N. Mikhailov (5, 6) , S. A. Dvoretskii (6, 5) , W. Knap (7) , F. Teppe (7)

1 L2C - Laboratoire Charles Coulomb
2 IES - Institut d’Electronique et des Systèmes
3 TéHO - Térahertz, hyperfréquence et optique
4 Institute for Physics of Microstructures of the RAS
5 Institute of Semiconductor Physics, Novosibirsk
6 NSU - Novosibirsk State University
7 GES - Groupe d'étude des semiconducteurs

We report on the temperature-dependent magneto absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells above the critical well thickness d(c). Our results, obtained in magnetic fields up to 16 T and temperature range from 1.7 to 150 K, clearly indicate a change in the band-gap energy with temperature. A topological phase transition between quantum spin Hall and trivial insulator states, revealing appearance of single-valley Dirac fermions at T = 27 and 90 K for 6.5 and 8 nm QWs respectively, was clearly observed in our magnetospectroscopy measurements.

Domaines: Matière Condensée [cond-mat]

A. M. Kadykov, Sergey S. Krishtopenko, Benoit Jouault, W. Desrat, M. Marcinkiewicz, et al.. Spectroscopy of temperature-driven single valley Dirac fermions in HgTe/CdHgTe quantum wells. 2018 43RD INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ), Sep 2018, 345 E 47TH ST, NEW YORK, NY 10017 USA, Unknown Region. ⟨10.1109/IRMMW-THz.2018.8510039⟩. ⟨hal-03037689⟩