Fermi arcs in the type-II Weyl semimental candidates WTe2 and MoTe2 investigated by laser-based ARPES

25.09.2018 13:00 – 14:00

Weyl semimetals are commonly identified by detecting surface states forming characteristic Fermi arcs in angle-resolved photoemission (ARPES) experiments. However, in type-II Weyl semimetals the Fermi arcs generally disappear in the bulk carrier pockets before reaching the Weyl points where they terminate - making it harder to unambiguously identify this new electronic state.
Using laser-based ARPES, we have resolved multiple distinct Fermi arcs on the inequivalent top and bottom (001) surfaces of the candidate type-II Weyl semimetal WTe2 and MoTe2. By comparing our ARPES data with systematic electronic structure calculations simulating different Weyl point arrangements, we show that some of these arcs are “false positives” as they are not related to Weyl points, while others are only reproduced in scenarios with at least eight Weyl points. For MoTe2, all surface states observed experimentally are well reproduced by a calculation that predicts a topological type-II Weyl semimetal state.

Lieu

Bâtiment: Ecole de Physique

auditoire Stuckelberg

Organisé par

Département de physique de la matière quantique

Intervenant-e-s

Anna TAMAI , DQMP, UNIGE

entrée libre

Classement

Catégorie: Séminaire