Joint Annual Meeting of SPS and ÖPG 2019

【618】Emergent topology in a 3D Kane-Mele system: Pt2HgSe3

27 Aug 2019, 18:45

15m

G 85

Talk MaNEP Session: Correlations and topology in quantum matter MaNEP: Correlations and topology in quantum matter

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.