Work

Orthogonal flatbands in Hamiltonians with local symmetry

Year: 2024

Type: article

Abstract: We derive symmetry-based conditions for tight-binding Hamiltonians with flatbands to have compact localized eigenstates (CLS) occupying a single unit cell. The conditions rely on unitary operators commuting with the Hamiltonian and are associated with local symmetries that ensure the existence of orthogonal compact localized states and a flatband. We also demonstrate the inverse: orthogonal flatbands, whose CLS can be made to occupy a single unit cell, always have associated local symmetries that satisfy our conditions.We illustrate our analytical result with several model Hamiltonians with given local symmetries, including examples with finite-range hopping and higher-dimensional ones.

Source: Journal of Physics A Mathematical and Theoretical

DOI: 10.1088/1751-8121/ad909d

Authors: Jung-Wan Ryu, Alexei Andreanov, Hee Chul Park, Jae-Ho Han

Institutions: Institute for Basic Science, Korea University of Science and Technology, Pukyong National University, Korea Advanced Institute of Science and Technology

Language: English

Topic: Topological Materials and Phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Ministry of Education, National Research Foundation of Korea, Institute for Basic Science

Awards: G1369937091, G2839496562, G8332058331