Surface reconstruction limited magnetism of the nodal loop semimetal Ca$_3$P$_2$

TL;DR

This study explores how surface reconstruction and lattice termination influence magnetism in Ca$_3$P$_2$ nodal loop semimetals, revealing that slight deviations in calcium occupation can stabilize magnetic patterns.

Contribution

It demonstrates that surface reconstruction and non-stoichiometry significantly affect surface magnetism in Ca$_3$P$_2$, a topological nodal loop semimetal.

Findings

Surface reconstruction impacts magnetic properties.

Non-stoichiometric calcium occupation stabilizes magnetism.

Magnetic patterns are sensitive to surface and lattice modifications.

Abstract

Nodal loop semimetals are topological materials with drumhead surface states characterized by reduced kinetic energy. If the Fermi energy of such a system is near these nondispersive states interaction among charge carriers substantially impacts their electronic structure. The emergence of magnetism in these surface states is one of the possible consequences. Ca3P2 an already synthesized material possesses a remarkably large nodal loop which is situated exactly at the Fermi level of the bulk system. In the present work, we investigate how surface magnetism is impacted by surface reconstruction and lattice termination in finite slabs in this material. We show that a slight deviation from the stoichiometric occupation of Ca sites results in the stabilization of magnetic patterns.