Geometry and topology in superlattice materials
Abstract
A recent breakthrough in condensed matter physics is the discovery of superconductivity in two atomically thin layers of carbon, layered with a small relative twist angle. This discovery is exciting for its novelty, as well as for its simplicity. Importantly, it presents a tunable recipe to achieve novel emergent phases of matter. One of the defining features of this system is its large moir e superlattice pattern. The proposed theoretical work seeks to determine whether artificially engineered superlattices without a moir e pattern can exhibit similarly exciting phases of matter. Of particular interest is the fractional Chern insulator, in which electrons behave as though they are split into quasiparticles with fractional charge. The proposed work has three main objectives- 1) optimize the superlattice geometry and tunable parameters to realize a fractional Chern insulator in bilayer graphene subject to a superlattice potential; 2) determine whether a superlattice potential on the surface of a topological insulator can increase the superconducting and magnetic critical temperatures and propose improved material platforms; and 3) develop a theory to determine the topology of a 2D material subject to a weak superlattice potential based only on the symmetry and geometry of the material before the superlattice is applied. The theory can be applied to new superlattice materials as they arise. The work will be accomplished through analytical and numerical calculations. The end product will be optimized materials to realize correlated topological phases and a symmetry-based theory to predict topological flat bands in 2D superlattice materials.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410222
Entities
People
- Jennifer Cano
Organizations
- Air Force Office of Scientific Research
- Research Foundation for the State University of New York
- United States Air Force