Electronic commensuration of a spin moiré superlattice in a layered magnetic semimetal.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39908386.
- Also identified by DOI 10.1126/sciadv.adu6686 and PMC identifier 11797546.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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 <i>J</i> is transmitted between conduction electrons and localized spins. Furthermore, most systems have carrier mean free paths <i>l</i><sub>mfp</sub> shorter than their spin moiré lattice constant <i>a</i><sub>spin</sub>, inhibiting miniband formation. Here, we discover that the layered magnetic semimetal EuAg<sub>4</sub>Sb<sub>2</sub> overcomes these challenges by forming an interface with <i>J</i> ~ 100 milli-electron volts transferred between a Eu triangular lattice and anionic Ag<sub>2</sub>Sb bilayers hosting a two-dimensional electron band in the ballistic regime (<i>l</i><sub>mfp</sub> >> <i>a</i><sub>spin</sub>). The system realizes an SMS with <i>a</i><sub>spin</sub> 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.