Jeu. 15/02/2018 11:00 Salle des Séminaires, Bâtiment 21, Etage 4
ASSAF Badih a. (Département de Physique, Ecole Normale Supérieure, PSL, CNRS)
Bulk and surface signatures of non-trivial band topology in Pb1-xSnxSe
Pb1-xSnxSe (x>0.16) topological crystalline insulators host massless surface Dirac cones stemming from a band inversion that occurs at the mirror symmetric L-points of the Brillouin zone , . In this talk, I will present two experimental observables related to the emergence of the topological phase in Pb1-xSnxSe. First, I will show how bulk transport is uniquely altered by the band inversion, and exhibits a negative magnetoresistance when the system is in the quantum limit . Second, I will demonstrate the emergence of topological interface states at a topological-trivial junction formed between Pb0.75Sn0.25Se and Pb1-yEuySe. Using infrared Landau level spectroscopy, I will present our results evidencing the robustly Dirac-like nature of these surface states up to 15T, and their mass acquisition and suppression as a function of increasing temperature and quantum confinement . Overall, I will argue throughout my talk that Pb1-xSnxSe is – truly – a model system to study topological phase of matter.
Pour plus d'informations, merci de contacter Teppe F.