Topological gaps by twisting
Abstract
Twisted bilayered systems such as bilayered graphene exhibit remarkable properties such as superconductivity at magic angles and topological insulating phases. For generic twist angles, the bilayers are truly quasiperiodic, a fact that is often overlooked and that has consequences which are largely unexplored. Herein, we uncover that twisted n-layers host intrinsic higher dimensional topological phases, and that those characterized by second Chern numbers can be found in twisted bi-layers. We employ phononic lattices with interactions modulated by a second twisted lattice and reveal Hofstadter-like spectral butterflies in terms of the twist angle, which acts as a pseudo magnetic field. The phason provided by the sliding of the layers lives on 2n-tori and can be used to access and manipulate the edge states. Our work demonstrates how multi-layered systems are virtual laboratories for studying the physics of higher dimensional quantum Hall effect, and can be employed to engineer topological pumps via simple twisting and sliding.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 11, 2021
- Source ID
- 10.1038/s42005-021-00630-3
Entities
People
- Emil Prodan
- Massimo Ruzzene
- Matheus I. N. Rosa
Organizations
- Army Research Office
- Division of Materials Research
- National Science Foundation Directorate for Engineering