Tuning the electronic structure in~nearly gapless HgCdTe with temperature: infrared magneto-spectroscopy study\textbf{~}
ORAL
Abstract
Replace this text with your abstract body. Recently,~a temperature-induced transition from a conventional two-dimensional semiconductor to a topological insulator has been demonstrated through magneto transport studies on HgTe/CdHgTe quantum~wells [Wiedmann, S. et al. Phys. Rev. B 91, 205311 (2015)]. Here we report on a temperature-driven semiconductor-to-semimetal transition in 3-dimensional CdxHg1-xTe (x$=$0.15) revealed by infrared magneto-spectroscopy. ~We show that changing the temperature from~4K to 120K enables~continuous~tuning of the band structure from inverted to normal alignment through a critical gapless state realized at \textasciitilde 80K, where the inter-Landau level transitions exhibit a characteristic~~sqrt(B) dependence intersecting at zero energy. Using an effective Dirac model, we determine the effective mass and the Fermi velocity for the studied temperature range. ~
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