Magnetic domain structure and domain wall bound states of topological semimetal EuB6

TL;DR

This paper investigates the magnetic domain structures and bound states at domain walls in the topological semimetal EuB6, revealing potential for electric control of magnetic domains in spintronic applications.

Contribution

It combines first principles calculations and magnetic force microscopy to identify robust domain wall bound states in EuB6, a magnetic Weyl semimetal, highlighting their topological and charge localization properties.

Findings

Domains with magnetization along three [100] directions dominate under small magnetic fields.

First principles calculations show robust domain wall bound states with extensive spectral distribution.

Localized charges at domain walls could enable electric-driven domain wall motion.

Abstract

Electrically manipulating domain wall (DW) is at central in the field of spintronics. Magnetic Weyl semimetal (WSM) offers an additional knob for electric manipulation of DW by utilizing the topological DW bound states. Using magnetic WSM material EuB6 as a prototype system, we investigate its DW bound states combining first principles calculations and domain imaging via magnetic force microscopy (MFM). The MFM measurements reveal that domains with magnetization aligned along three [100] directions dominate over others under a small magnetic field along [001] direction. Accordingly, first principles calculations are performed based on experimentally determined DW type, which show a robust DW bound state featuring a spectral distribution over a large portion of the DW Brillouin zone. Such DW bound states should result in significant amount of localized charges which can be used to drive DW motion via the electrostatic forces exerted on the localized DW charges.