Searcharxiv⌕ Search

arXiv subjects

Hyeok-Cheol Choi

Publications and source records attributed to Hyeok-Cheol Choi.

2 recordsLinked to original sources
arXiv2017

Empirical correlation between the interfacial Dzyaloshinskii Moriya interaction and work function in metallic magnetic trilayers

The Dzyaloshinskii Moriya interaction (DMI) generates intriguing chiral magnetic objects such as magnetic skyrmions and chiral domain walls that can be used as building blocks in emerging magnetic nanodevices. To achieve better stability and functionality of these chiral objects, it is essential to achieve a larger DMI. In this paper, we report an experimental observation that in magnetic trilayer films, the DMI strength is mainly determined by the work functions of the nonmagnetic layers interfaced with the magnetic layer. The clear correlation with the intrinsic material parameters provides a guideline for material selection to engineer the DMI strength.

cond-mat.mtrl-sci↗
arXiv2017

Magnetic Domain-Wall Tilting due to Domain-Wall Speed Asymmetry

Chiral magnetic materials provide a number of challenging issues such as the highly efficient domain wall (DW) and skyrmion motions driven by electric current, as of the operation principles of emerging spintronic devices. The DWs in the chiral materials exhibit asymmetric DW speed variation under application of in plane magnetic field. Here, we show that such DW speed asymmetry causes the DW tilting during the motion along wire structure. It has been known that the DW tilting can be induced by the direct Zeeman interaction of the DW magnetization under application of in plane magnetic field. However, our experimental observations manifests that there exists another dominant process with the DW speed asymmetry caused by either the Dzyaloshinskii Moriya interaction (DMI) or the chirality dependent DW speed variation. A theoretical model based on the DW geometry reveals that the DW tilting is initiated by the DW pinning at wire edges and then, the direction of the DW tilting is determined by the DW speed asymmetry, as confirmed by a numerical simulation. The present observation reveals the decisive role of the DW pinning with the DW speed asymmetry, which determines the DW geometry and consequently, the dynamics.

cond-mat.mtrl-sci↗