Year: 2024
Type: article
Abstract: Twisted bilayers host many emergent phenomena in which the electronic excitations (quasiparticles, QPs) are closely intertwined with the local stacking order. By inspecting twisted hexagonal boron nitride (t-hBN), we show that nonlocal long-range interactions in large twisted systems cannot be reliably described by the local (high-symmetry) stacking and that the band gap variation (typically associated with the moiré excitonic potential) shows multiple minima with variable depth depending on the twist angle. We investigate twist angles of 2.45°, 2.88°, 3.48°, and 5.09° using the GW approximation together with stochastic compression to analyze the QP state interactions. We find that band-edge QP hybridization is suppressed for intermediate angles that exhibit two distinct local minima in the moiré potential (at AA region and saddle point (SP)) which become degenerate for the largest system (2.45°).
Source: Nano Letters
Authors: Arsineh Apelian, Annabelle Canestraight, Songyuan Liu, Vojtěch Vlček
Institution: University of California, Santa Barbara
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, United States-Israel Binational Science Foundation, Tel Aviv University, China Scholarship Council, University of California, Santa Barbara, Materials Research Science and Engineering Center, Harvard University, Office of the President, University of California, Division of Materials Research, California NanoSystems Institute, National Science Foundation Graduate Research Fellowship Program
Awards: G1110399006, G1141670404, G1642001521, G2232042528, G2760720504, CAREER: Stochastic Methods for Electronic Excitations in Complex Nanoscale System, Materials Research Science and Engineering Center at UCSB, G3349485200, G3400352658, G401861217, G4281768896, G4481045994, Graduate Research Fellowship Program (GRFP), G6070405715, The California Interfacial Science Institute (CISI), G6671297155, G7489972311, G8094494984, MRI: Acquisition of a High Performance Central Computing Facility at University of California Santa Barbara
OpenAlex ID: W4402580176