Metastable magnetic domains and the anomalous $B_\parallel=0$ resistance peak in twisted double bilayer graphene
Year: 2026
Type: preprint
Abstract: In graphene moirés, valley polarization gives rise to orbital magnetism, manifested as an anomalous Hall effect and resulting in Barkhausen jumps in longitudinal resistance when changing domain configurations modify quasiparticle scattering. Beyond a simple picture of polarized domains, however, spin and valley textures within and between the domains are less well understood, as is the effect of these textures on transport. In the valley-polarized quarter-metal state of twisted double bilayer graphene, a sharp and metastable peak in longitudinal resistance often appears at zero in-plane magnetic field, whose microscopic origin has yet to be identified. Here, we show that this peak depends on the configuration of domains of orbital magnetism, which is itself set by the gate-voltage trajectory used to enter the ordered state and by the magnetic field --- particularly the in-plane component --- present during that trajectory. The sensitivity of the effect to in-plane magnetic field components points to spin, linked to valley polarization through spin-orbit coupling, as the key degree of freedom in both the domain formation and the resistance peak.
Source: arXiv (Cornell University)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, European Commission, Ministry of Education, Culture, Sports, Science and Technology, University of Tokyo, Canada First Research Excellence Fund, Natural Sciences and Engineering Research Council of Canada, Japan Society for the Promotion of Science, Division of Materials Research, Basic Energy Sciences
OpenAlex ID: W7204446153