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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Impurity-induced triple point fermions in twisted bilayer graphene

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Author(s):
Ramires, Aline [1, 2] ; Lado, Jose L. [3]
Total Authors: 2
Affiliation:
[1] Univ Estadual Paulista, Inst Fis Teor, BR-01140070 Sao Paulo, SP - Brazil
[2] South Amer Inst Fundamental Res, Int Ctr Theoret Phys, BR-01140070 Sao Paulo, SP - Brazil
[3] Swiss Fed Inst Technol, Inst Theoret Phys, CH-8093 Zurich - Switzerland
Total Affiliations: 3
Document type: Journal article
Source: Physical Review B; v. 99, n. 24 JUN 10 2019.
Web of Science Citations: 2
Abstract

Triple point fermions are elusive electronic excitations that generalize Dirac and Weyl modes beyond the conventional high-energy paradigm. Yet, finding real materials naturally hosting these excitations at the Fermi energy has remained challenging. Here we show that twisted bilayer graphene is a versatile platform to realize robust triple point fermions in two dimensions. In particular, we establish that the introduction of localized impurities lifts one of the two degenerate Dirac cones, yielding triple point fermions at charge neutrality. Furthermore, we show that the valley polarization is preserved for certain impurity locations in the Moire supercell for both weak and strong impurity potentials. We finally show that in the presence of interactions, a symmetry-broken state with local magnetization can develop out of the triple point bands, which can be selectively controlled by electrostatic gating. Our results put forward twisted bilayer graphene as a simple solid-state platform to realize triple point fermions at charge neutrality and demonstrate the nontrivial role of impurities in Moire systems. (AU)

FAPESP's process: 18/04955-9 - New theoretical tools for the understanding and optimization of emergent phases of matter in complex materials
Grantee:Aline Ramires Neves de Oliveira
Support type: Research Grants - Young Investigators Grants
FAPESP's process: 18/18287-8 - New theoretical tools for the understanding and optimization of emergent phases of matter in complex materials
Grantee:Aline Ramires Neves de Oliveira
Support type: Scholarships in Brazil - Young Researchers