Intrinsic i-wave altermagnetism in 2D graphene superlattices

TL;DR

This paper demonstrates the design and emergence of i-wave altermagnetic states in graphene superlattices, revealing a new carbon-based platform for altermagnetic spintronics through symmetry-guided engineering and first-principles calculations.

Contribution

It introduces a symmetry-guided approach to engineer i-wave altermagnetism in graphene antidot superlattices, a previously elusive carbon-based altermagnetic system.

Findings

Altermagnetic states emerge in specific graphene superlattices.

Interaction-induced i-wave altermagnetic splitting observed.

Strategy established for engineering altermagnetism in graphene.

Abstract

Altermagnets feature unconventional magnetism due to their momentum-dependent spin splitting purely driven by magnetic order, for which a variety of transition-metal-based d-wave altermagnets have been proposed. However, carbon-based altermagnets in graphene structures remain elusive, even though magnetism in graphene nanostructures has been widely demonstrated. Here, we establish a symmetry-guided design principle to engineer i-wave altermagnets in graphene antidot superlattices and demonstrate the emergence of altermagnetic states in specific monolayer and bilayer graphene superlattices. By combining first principles methods and atomistic tight binding models, we show the appearance of an interaction-induced i-wave altermagnetic splitting, stemming from the intrinsic magnetic instability of 2D graphene antidot superlattices. Our work establishes a strategy to engineer i-wave altermagnetism in a graphene platform, putting forward a carbon-based platform for altermagnetic spintronics.