Giant interfacial Dzyaloshinskii-Moriya Interaction in perovskite La_{0.7}Sr_{0.3}MnO_{3} films

TL;DR

This paper reports the discovery of a giant interfacial Dzyaloshinskii-Moriya interaction in La_{0.7}Sr_{0.3}MnO_{3} films on certain substrates, which is significantly larger than previously observed in oxides, due to interface engineering and electron interactions.

Contribution

The study demonstrates a giant interfacial DMI in oxide films and elucidates its origin through first-principles calculations involving electron interactions at the interface.

Findings

Interfacial DMI coefficient of 1.96 pJ/m in LSMO/NdGaO_{3}

Giant DMI exceeds previous oxide values by one to two orders of magnitude

Nd's 4f electrons and Mn's 3d electrons enhance spin-orbit coupling

Abstract

The Dzyaloshinskii-Moriya interaction (DMI) plays a critical role in stabilizing topological spin textures, a key area of growing interest in oxide-based spintronics. While most of reported topological phenomena found in manganites are related to the bulk-like DMI, the understanding of interfacial DMI and its origin in oxide interfaces remain limited. Here we experimentally investigate the interfacial DMI of La_{0.7}Sr_{0.3}MnO_{3} (LSMO) films grown on various substrates by employing spin-wave propagation with drift velocities at room temperature. Our findings reveal a giant interfacial DMI coefficient (\mathit{D} _{s}) of 1.96 pJ/m in LSMO/NdGaO_{3}(110) system, exceeding previously reported values in oxides by one to two orders of magnitude. First-principles calculations further show that with the aid of 6\mathit{s} electrons, the 4\mathit{f} electrons from Nd play a key role in enhancing the spin-orbit coupling of the 3\mathit{d} electrons in Mn, ultimately leading to the observed giant interfacial DMI. This discovery of giant interfacial DMI through engineering the interface of oxides provides valuable insights for advancing functional chiral magnonics and spintronics.