Magnetism and berry phase manipulation in an emergent structure of perovskite ruthenate by (111) strain engineering

TL;DR

This study demonstrates how strain engineering along the (111) axis induces a trigonal structure in SrRuO3, leading to novel magnetic and topological properties, including Weyl nodes and anomalous Hall effects, revealing new avenues for topological material design.

Contribution

The paper introduces a method to create a trigonal SrRuO3 structure via strain engineering, revealing its magnetic and topological properties with Weyl nodes and Berry phase effects, which were not previously observed in bulk form.

Findings

Emergent trigonal SrRuO3 exhibits XY-type ferromagnetism.

Presence of Weyl nodes confirmed by anomalous Hall effect.

First-principles calculations support observed band topology.

Abstract

The interplay among symmetry of lattices, electronic correlations, and Berry phase of the Bloch states in solids has led to fascinating quantum phases of matter. A prototypical system is the magnetic Weyl candidate SrRuO3, where designing and creating electronic and topological properties on artificial lattice geometry is highly demanded yet remains elusive. Here, we establish an emergent trigonal structure of SrRuO3 by means of heteroepitaxial strain engineering along the [111] crystallographic axis. Distinctive from bulk, the trigonal SrRuO3 exhibits a peculiar XY-type ferromagnetic ground state, with the coexistence of high-mobility holes likely from linear Weyl bands and low-mobility electrons from normal quadratic bands as carriers. The presence of Weyl nodes are further corroborated by capturing intrinsic anomalous Hall effect, acting as momentum-space sources of Berry curvatures. The experimental observations are consistent with our first-principles calculations, shedding light on the detailed band topology of trigonal SrRuO3 with multiple pairs of Weyl nodes near the Fermi level. Our findings signify the essence of magnetism and Berry phase manipulation via lattice design and pave the way towards unveiling nontrivial correlated topological phenomena.