Speaker
Irène Cucchi
(Universtié de Genève)
Description
Monolayer jacutingaite (Pt$_2$HgSe$_3$) was recently predicted to be a Kane-Mele Quantum Spin Hall insulator (QSHI), with a topological gap as large as 0.5 eV. We investigated the electronic band structure of bulk single crystals by angle-resolved photoemission. Surprisingly, on the (001) surface, we observed surface states dispersing over large areas of the Brillouin zone, which is unexpected from a 3D stack of 2D QSHI. Using a minimal description that extends the Kane-Mele model to 3D, we demonstrate that these states are topologically protected indicating that bulk Pt$_2$HgSe$_3$ realizes a new form of topological (quantum band) semimetal.
Author
Irène Cucchi
(Universtié de Genève)
Co-authors
Prof.
Felix Baumberger
(Université de Genève)
Dr
Enrico Giannini
(Université de Genève)
Mr
Antimo Marrazzo
(Ecole Polytechnique Fédérale de Lausanne)
Dr
Marco Gibertini
(Université de Genève)
Dr
Anna Tamai
(Université de Genève)