AC Current-Driven Magnetization Switching and Nonlinear Hall Rectification in a Magnetic Topological Insulator.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41085086.
- Also identified by DOI 10.1002/adma.202506210 and PMC identifier 12810608.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Spin-orbit torque arising from the spin-orbit-coupled surface states of topological insulators enables current-induced control of magnetization with high efficiency. Here, alternating-current (AC) driven magnetization reversal is demonstrated in a semi-magnetic topological insulator (Cr,Bi,Sb)<sub>2</sub>Te<sub>3</sub>/(Bi,Sb)<sub>2</sub>Te<sub>3</sub>, facilitated by a low threshold current density of 1.5 × 10<sup>9</sup> A m<sup>-2</sup>. Time-domain Hall voltage measurements using an oscilloscope reveal a strongly nonlinear and rectified Hall response during the magnetization reversal process. Fourier analysis of the time-varying Hall voltage identifies higher-harmonic signals and a rectified direct-current (DC) component, highlighting the complex interplay among the applied current, external magnetic field, and magnetization dynamics. Furthermore, a hysteretic behavior in the current-voltage characteristics gives rise to frequency mixing under dual-frequency excitation. This effect, distinct from conventional polynomial-based nonlinearities, allows for selective extraction of specific frequency components. The results demonstrate that AC excitation can not only switch magnetization efficiently but also induce tunable nonlinear responses, offering a new pathway for multifunctional spintronic devices with potential applications in energy-efficient memory, signal processing, and frequency conversion.