| Full text | |
| Author(s): |
Ramires, Aline
;
Lado, Jose L.
Total Authors: 2
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW B; v. 99, n. 24, p. 7-pg., 2019-06-10. |
| 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 Opportunities: | 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 Opportunities: | Scholarships in Brazil - Young Researchers |