PbSnSe: a model system to study topological phases
ORAL
Abstract
Pb1-xSnxSe hosts three-dimensional (3D) massive Dirac fermions across the entire composition range for which the crystal structure is cubic. In this talk, we will present a comprehensive experimental mapping of the 3D band structure of Pb1-xSnxSe as a function of chemical composition (0<x<0.3), temperature (1.6<T<200 K), and magnetic field (0<B<34 T). We use magneto-infrared spectroscopy to determine all the Dirac parameters in the trivial and topologically non-trivial regimes.
In 3D Pb1-xSnxSe topological insulators, an effective closure of the bulk energy gap with increasing temperature, magnetic field, or lead content is expected at the critical point of the phase transition. However, in this talk we experimentally demonstrate that such a gap closure consistently does not occur. Avoided-crossing of either bulk bands or N=0 Landau levels are evidenced. These results show that Pb1-xSnxSe is a model system to study topological phases and the nature of the phase transition.
In 3D Pb1-xSnxSe topological insulators, an effective closure of the bulk energy gap with increasing temperature, magnetic field, or lead content is expected at the critical point of the phase transition. However, in this talk we experimentally demonstrate that such a gap closure consistently does not occur. Avoided-crossing of either bulk bands or N=0 Landau levels are evidenced. These results show that Pb1-xSnxSe is a model system to study topological phases and the nature of the phase transition.
*This work is supported by Agence Nationale de la Recherche LabEx ENS-ICFP Grant No ANR-10-LABX-0010/ANR-10-IDEX-0001-02 PSL and by the Austrian Science Fund, Projects P 28185-N27 and P 29630-N27. It is also partly supported by a PSL scholarship.
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Presenters
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Gauthier Krizman
- Department of Physics, Ecole Normale Superieure
- Physics, Ecole Normale Superieure