Visualizing orbital magnetism in electron doped rhombohedral multilayer graphene
8 affiliations
- 1Physics Department , University of California , Santa Barbara 93106
- 2Department of Physics , Stanford University , Stanford , CA 94305
- 3Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , CA 94025
- 4Department of Materials Science and Engineering , Stanford University , Stanford , CA 94305
- 5Departments of Physics and Electrical Engineering , University of Colorado , Denver , Colorado 80204 , USA
- 6Research Center for Materials Nanoarchitectonics , National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan
- 7Research Center for Electronic and Optical Materials , National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan
- 8Département de physique , Institut quantique & RQMP , Université de Sherbrooke , Sherbrooke , Québec J1K 2R1 , Canada
Abstract
Electron doped rhombohedral multilayer graphene at high displacement field features an exceptionally flat band minimum with near-ideal quantum geometry. Experiments in this regime observe the formation of a 'quarter metal,' in which the electron liquid condenses into a single spin- and valley flavor. Remarkably, recent experiments have found a zero resistance state in the same region of the density- and displacement-field-tuned parameter space, attributed to the formation of a chiral superconductor from an orbitally ferromagnetic normal state. Here, we use nanoSQUID-on-tip magnetometry to map the orbital magnetization of electron-doped rhombohedral graphene devices ranging in thickness between 3 and 15 layers. Magnetization within the quarter metal phases peaks at finite density, consistent with concentration of the Berry curvature in a finite-momentum 'ring of fire'. Correlating transport and local magnetometry data in a superconducting tetralayer sample reveals a finite orbital ferromagnetic moment, providing direct evidence of valley polarization in the superconducting ground state. We further show that widely observed stochastic switching of the resistivity in both metallic and superconducting regimes arises from a density-tuned sign change in the valley-resolved total magnetic moment. This leads to the formation of metastable magnetic domains under typical gate control sequences and can also be harnessed for electric-field controlled switching of the magnetization across the entire device. Finally, high resolution measurements of the magnetization across a superconducting transition allow us to put an upper bound on the 'condensation magnetization' of 0.1 Bohr magneton per carrier, placing a strong quantitative restriction on theoretical models for ferromagnetic superconductivity.
Related
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BibTeX
@misc{sheekey2026visualizing,
title = {{Visualizing orbital magnetism in electron doped rhombohedral multilayer graphene}},
author = {Owen Sheekey and Trevor Arp and Benjamin A. Foutty and Ruoxi Zhang and Tixuan Tan and Ludwig Holleis and Yi Guo and Sandesh S. Kalantre and Canxun Zhang and Mark Zakharyan and David Gong and Aidan Keough and Youngjoon Choi and Ysun Choi and Siyuan Xu and Tian Xie and Ben Hodder Alexander and Marisa Hocking and Qingrui Cao and M. E. Huber and Takashi Taniguchi and Kenji Watanabe and Chenhao Jin and Étienne Lantagne-Hurtubise and Aaron L. Sharpe and Trithep Devakul and Andrea F. Young},
howpublished = {arXiv (Cornell University)},
year = {2026},
month = may,
doi = {10.48550/arxiv.2605.30316},
url = {https://arxiv.org/abs/2605.30316},
note = {CC BY},
}
RIS
TY - UNPB
TI - Visualizing orbital magnetism in electron doped rhombohedral multilayer graphene
AU - Owen Sheekey
AU - Trevor Arp
AU - Benjamin A. Foutty
AU - Ruoxi Zhang
AU - Tixuan Tan
AU - Ludwig Holleis
AU - Yi Guo
AU - Sandesh S. Kalantre
AU - Canxun Zhang
AU - Mark Zakharyan
AU - David Gong
AU - Aidan Keough
AU - Youngjoon Choi
AU - Ysun Choi
AU - Siyuan Xu
AU - Tian Xie
AU - Ben Hodder Alexander
AU - Marisa Hocking
AU - Qingrui Cao
AU - M. E. Huber
AU - Takashi Taniguchi
AU - Kenji Watanabe
AU - Chenhao Jin
AU - Étienne Lantagne-Hurtubise
AU - Aaron L. Sharpe
AU - Trithep Devakul
AU - Andrea F. Young
PY - 2026
DA - 2026/05/28
PB - arXiv (Cornell University)
DO - 10.48550/arxiv.2605.30316
UR - https://arxiv.org/abs/2605.30316
AB - Electron doped rhombohedral multilayer graphene at high displacement field features an exceptionally flat band minimum with near-ideal quantum geometry. Experiments in this regime observe the formation of a 'quarter metal,' in which the electron liquid condenses into a single spin- and valley flavor. Remarkably, recent experiments have found a zero resistance state in the same region of the density- and displacement-field-tuned parameter space, attributed to the formation of a chiral superconductor from an orbitally ferromagnetic normal state. Here, we use nanoSQUID-on-tip magnetometry to map the orbital magnetization of electron-doped rhombohedral graphene devices ranging in thickness between 3 and 15 layers. Magnetization within the quarter metal phases peaks at finite density, consistent with concentration of the Berry curvature in a finite-momentum 'ring of fire'. Correlating transport and local magnetometry data in a superconducting tetralayer sample reveals a finite orbital ferromagnetic moment, providing direct evidence of valley polarization in the superconducting ground state. We further show that widely observed stochastic switching of the resistivity in both metallic and superconducting regimes arises from a density-tuned sign change in the valley-resolved total magnetic moment. This leads to the formation of metastable magnetic domains under typical gate control sequences and can also be harnessed for electric-field controlled switching of the magnetization across the entire device. Finally, high resolution measurements of the magnetization across a superconducting transition allow us to put an upper bound on the 'condensation magnetization' of 0.1 Bohr magneton per carrier, placing a strong quantitative restriction on theoretical models for ferromagnetic superconductivity.
SN - 2331-8422
ER -