Speaker
Description
Moiré materials represent one of the richest fields in condensed matter physics, with twisted
bilayer graphene (TBG) serving as a prime example. TBG exhibits exotic physical properties,
including unconventional superconductivity and delocalized eigenstates in both momentum
and real space near the flat-band regime. Recent experiments on hBN/TBG and twisted trilayer
graphene (TTG) have uncovered a new, intrinsically quasiperiodic regime driven by competing
incommensurate moirés, dubbed moiré quasicrystals. Because these phases also host robust
correlated states, understanding the exact role of quasiperiodicity is essential to determine
whether such phenomena are driven by correlation, topology, or the explicit breaking of
translational invariance.
To address this, we perform real-space atomistic tight-binding simulations of 2D moiré
materials containing up to 15 million atoms. By comparing quasiperiodic and commensurate
(unit cell = 1 moiré cell) TBG, we conduct a multifractal analysis of the local density of states to
extract the singularity spectrum, a quantity directly accessible to experimentalists via STS
maps. Our results show that incommensurate magic-angle TBG, the flat band is strictly
multifractal, whereas commensurate structures remain monofractal.
We acknowledge support from Fundação para a Ciência e a Tecnologia through Grant No. UID/
04650/2025 and project QPIMoireS (DOI: 10.54499/2023.17745.ICDT).
| Which topic best fits your talk? | Condensed Matter Physics and Nanomaterials |
|---|---|
| Affiliations | Universidade do Porto Faculdade de Ciências |