Nonlocal Interactions in Moir\'e Hubbard Systems

Nonlocal Interactions in Moiré Hubbard Systems

Nicolás Morales-Durán, Nai Chao Hu, Pawel Potasz, and Allan H. MacDonald

Phys. Rev. Lett. 128, 217202 – Published 24 May 2022

Abstract

Moiré materials formed in two-dimensional semiconductor heterobilayers are quantum simulators of Hubbard-like physics with unprecedented electron density and interaction strength tunability. Compared to atomic scale Hubbard-like systems, electrons or holes in moiré materials are less strongly attracted to their effective lattice sites because these are defined by finite-depth potential extrema. As a consequence, nonlocal interaction terms like interaction-assisted hopping and intersite exchange are more relevant. We theoretically demonstrate the possibility of tuning the strength of these coupling constants to favor unusual states of matter, including spin liquids, insulating ferromagnets, and superconductors.

Received 16 August 2021
Revised 19 January 2022
Accepted 2 May 2022

DOI:https://doi.org/10.1103/PhysRevLett.128.217202

Physics Subject Headings (PhySH)

Frustrated magnetism Magnetic order

Mott insulators Strongly correlated systems

Extended Hubbard model Heisenberg model

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Nicolás Morales-Durán ^1,*, Nai Chao Hu ¹, Pawel Potasz ², and Allan H. MacDonald¹

¹Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA
²Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Toruń, Poland