Deconfinement of Mott localized electrons into topological and spin–orbit-coupled Dirac fermions

  • The interplay of electronic correlations, spin–orbit coupling and topology holds promise for the realization of exotic states of quantum matter. Models of strongly interacting electrons on honeycomb lattices have revealed rich phase diagrams featuring unconventional quantum states including chiral superconductivity and correlated quantum spin Hall insulators intertwining with complex magnetic order. Material realizations of these electronic states are, however, scarce or inexistent. In this work, we propose and show that stacking 1T-TaSe2 into bilayers can deconfine electrons from a deep Mott insulating state in the monolayer to a system of correlated Dirac fermions subject to sizable spin–orbit coupling in the bilayer. 1T-TaSe2 develops a Star-of-David charge density wave pattern in each layer. When the Star-of-David centers belonging to two adyacent layers are stacked in a honeycomb pattern, the system realizes a generalized Kane–Mele–Hubbard model in a regime where Dirac semimetallic states are subject to significant Mott–Hubbard interactions and spin–orbit coupling. At charge neutrality, the system is close to a quantum phase transition between a quantum spin Hall and an antiferromagnetic insulator. We identify a perpendicular electric field and the twisting angle as two knobs to control topology and spin–orbit coupling in the system. Their combination can drive it across hitherto unexplored grounds of correlated electron physics, including a quantum tricritical point and an exotic first-order topological phase transition.

Download full text files

Export metadata

Metadaten
Author:José M. PizarroORCiD, Severino AdlerORCiDGND, Karim ZantoutORCiDGND, Thomas MertzORCiDGND, Paolo BaroneORCiD, Roser ValentíORCiDGND, Giorgio SangiovanniORCiDGND, Tim O. WehlingORCiDGND
URN:urn:nbn:de:hebis:30:3-823698
DOI:https://doi.org/10.1038/s41535-020-00277-3
ISSN:2397-4648
ArXiv Id:http://arxiv.org/abs/2001.04102
Parent Title (English):npj quantum materials
Publisher:Nature Publishing Group
Place of publication:[London]
Document Type:Article
Language:English
Date of Publication (online):2020/11/02
Date of first Publication:2020/11/02
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2024/02/19
Volume:5
Issue:Article number: 79
Article Number:79
Page Number:7
HeBIS-PPN:521024331
Institutes:Physik / Physik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - CC BY - Namensnennung 4.0 International