title: Temperature-driven massless Kane fermions in HgCdTe crystals.
abstract: It has recently been shown that electronic states in bulk gapless HgCdTe offer another realization of pseudo-relativistic three-dimensional particles in condensed matter systems. These single valley relativistic states, massless Kane fermions, cannot be described by any other relativistic particles. Furthermore, the HgCdTe band structure can be continuously tailored by modifying cadmium content or temperature. At critical concentration or temperature, the bandgap collapses as the system undergoes a semimetal-to-semiconductor topological phase transition between the inverted and normal alignments. Here, using far-infrared magneto-spectroscopy we explore the continuous evolution of band structure of bulk HgCdTe as temperature is tuned across the topological phase transition. We demonstrate that the rest mass of Kane fermions changes sign at critical temperature, whereas their velocity remains constant. The velocity universal value of (1.07±0.05) × 10(6) m s(-1) remains valid in a broad range of temperatures and Cd concentrations, indicating a striking universality of the pseudo-relativistic description of the Kane fermions in HgCdTe.
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.
authors: F
authors: F
authors: Teppe
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.
authors: M
authors: M
authors: Marcinkiewicz
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.|Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny, 603950 GSP-105 Novgorod, Russia.
authors: S S
authors: SS
authors: Krishtopenko
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.
authors: S
authors: S
authors: Ruffenach
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.
authors: C
authors: C
authors: Consejo
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.|Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny, 603950 GSP-105 Novgorod, Russia.
authors: A M
authors: AM
authors: Kadykov
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.
authors: W
authors: W
authors: Desrat
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.
authors: D
authors: D
authors: But
authors: Laboratoire Charles Coulomb, UMR CNRS 5221, University of Montpellier, Montpellier 34095, France.|Institute of High Pressure Institute Physics, Polish Academy of Sciences, 01-447 Warsaw, Poland.
authors: W
authors: W
authors: Knap
authors: National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.|Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors: J
authors: J
authors: Ludwig
authors: National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.|Department of Physics, Florida State University, Tallahassee, Florida 32306, USA.
authors: S
authors: S
authors: Moon
authors: National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
authors: D
authors: D
authors: Smirnov
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.|Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
authors: M
authors: M
authors: Orlita
authors: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors: Z
authors: Z
authors: Jiang
authors: Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny, 603950 GSP-105 Novgorod, Russia.|Lobachevsky State University of Nizhny Novgorod, Nizhny, 603950 Novgorod, Russia.
authors: S V
authors: SV
authors: Morozov
authors: Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny, 603950 GSP-105 Novgorod, Russia.|Lobachevsky State University of Nizhny Novgorod, Nizhny, 603950 Novgorod, Russia.
authors: V I
authors: VI
authors: Gavrilenko
authors: Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, pr. Akademika Lavrent'eva 13, 630090 Novosibirsk, Russia.|Novosibirsk State University, 630090 Novosibirsk, Russia.
authors: N N
authors: NN
authors: Mikhailov
authors: Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, pr. Akademika Lavrent'eva 13, 630090 Novosibirsk, Russia.|Novosibirsk State University, 630090 Novosibirsk, Russia.
authors: S A
authors: SA
authors: Dvoretskii