Engineering altermagnetic orders on the square-kagome lattice through sublattice interference

TL;DR

This paper explores how sublattice interference effects on the square-kagome lattice can induce and control altermagnetic phases with distinct magnetic orderings, offering new ways to engineer magnetic properties.

Contribution

It introduces a sublattice interference mechanism to realize and manipulate altermagnetic orders on the square-kagome lattice, using the Kotliar-Ruckenstein formalism.

Findings

Identification of $d_{xy}$-type altermagnetic phase

Identification of $d_{x^{2}-y^{2}}$-type altermagnetic phase

Sublattice-selective magnetic instabilities enable engineering of altermagnetic order

Abstract

We investigate the emergence of altermagnetic (AM) phases on the square-kagome lattice. Our analysis reveals that matrix element effects due to an orthogonal sublattice weight decomposition of Fermi level eigenstates known as sublattice interference enable decoupled magnetic ordering tendencies on distinct sublattices. Depending on which sublattice undergoes a magnetic instability, we identify a $d_{xy}$-type AM phase and a $d_{x^{2}-y^{2}}$-type AM phase originating from different sublattice polarization patterns. Using the Kotliar-Ruckenstein slave boson formalism we explore the stability of these AM phases as a function of interaction strength. Our findings demonstrate that sublattice-selective magnetic instabilities provide a versatile route to engineer the nature of AM order.