Electronic Commensuration of a Spin Moire Superlattice in a Layered Magnetic Semimetal

Published

February 4, 2025

Author(s)

Takashi Kurumaji, Nisarga Paul, Shiang Fang, Paul Neves, Mingu Kang, Jonathan White, Taro Nakajima, David Graf, Linda Ye, Mun Chan, Takehito Suzuki, Jonathan Denlinger, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, Jeffrey Lynn, Efthimios Kaxiras, Riccardo Comin, Liang Fu, Joseph Checkelsky, Yang Zhao

Abstract

Spin moiré superlattices (SMSs) have been proposed as a magnetic analog of crystallographic moiré systems and a source of electron minibands offering vector-field moiré tunability and Berry curvature effects. However, it has proven challenging to realize an SMS in which a large exchange coupling J is transmitted between conduction electrons and localized spins. Furthermore, most systems have carrier mean free paths lmfp shorter than their spin moiré lattice constant aspin, inhibiting miniband formation. Here, we discover that the layered magnetic semimetal EuAg4Sb2 overcomes these challenges by forming an interface with J 100 milli–electron volts transferred between a Eu triangular lattice and anionic Ag2Sb bilayers hosting a two-dimensional electron band in the ballistic regime (lmfp >> aspin). The system realizes an SMS with aspin commensurate with the Fermi momentum, leading to a marked quenching of the transport response from miniband formation. Our findings demonstrate an approach to magnetically engineering moiré superlattices and a potential route to an emergent spin-driven quantum Hall state.

Citation

Science Advances

Volume

11

Issue

6

Pub Type

Journals

Download Paper

https://doi.org/10.1126/sciadv.adu668

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Keywords

spin moiré superlattice, neutron diffraction, ARPES, DFT calculation, magnetization, topological bands, quantum oscillations, EuAg4Sb2

Citation

Kurumaji, T. , Paul, N. , Fang, S. , Neves, P. , Kang, M. , White, J. , Nakajima, T. , Graf, D. , Ye, L. , Chan, M. , Suzuki, T. , Denlinger, J. , Jozwiak, C. , Bostwick, A. , Rotenberg, E. , Lynn, J. , Kaxiras, E. , Comin, R. , Fu, L. , Checkelsky, J. and Zhao, Y. (2025), Electronic Commensuration of a Spin Moire Superlattice in a Layered Magnetic Semimetal, Science Advances, [online], https://doi.org/10.1126/sciadv.adu668, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935040 (Accessed July 8, 2025)