Néel Spin-Orbit Torque in Antiferromagnetic Quantum Spin and Anomalous Hall Insulators

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Tang, Junyu, Zhang, Hantao, Cheng, Ran
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911114382540800
author Tang, Junyu
Zhang, Hantao
Cheng, Ran
author_facet Tang, Junyu
Zhang, Hantao
Cheng, Ran
contents Interplay between magnetic ordering and topological electrons not only enables new topological phases but also underpins electrical control of magnetism. Here we extend the Kane-Mele model to include the exchange coupling to a collinear background antiferromagnetic (AFM) order, which can describe transition metal trichalcogenides. Owing to the spin-orbit coupling and staggered on-site potential, the system could exhibit the quantum anomalous Hall and quantum spin Hall effects in the absence of a net magnetization. Besides the chiral edge states, these topological phases support a staggered Edelstein effect through which an applied electric field can generate opposite non-equilibrium spins on the two AFM sublattices, realizing the Néel-type spin-orbit torque (NSOT). Contrary to known NSOTs in AFM metals driven by conduction currents, our NSOT arises from pure adiabatic currents devoid of Joule heating, while being a bulk effect not carried by the edge currents. By virtue of the NSOT, the electric field of a microwave can drive the AFM dynamics with a remarkably high efficiency. Compared to the ordinary AFM resonance driven by the magnetic field, the new mechanism can enhance the resonance amplitude by more than one order of magnitude and the absorption rate of the microwave power by over two orders of magnitude. Our findings unravel an incredible way to exploit AFM topological phases to achieve ultrafast magnetic dynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2410_21751
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Néel Spin-Orbit Torque in Antiferromagnetic Quantum Spin and Anomalous Hall Insulators
Tang, Junyu
Zhang, Hantao
Cheng, Ran
Mesoscale and Nanoscale Physics
Materials Science
Quantum Physics
Interplay between magnetic ordering and topological electrons not only enables new topological phases but also underpins electrical control of magnetism. Here we extend the Kane-Mele model to include the exchange coupling to a collinear background antiferromagnetic (AFM) order, which can describe transition metal trichalcogenides. Owing to the spin-orbit coupling and staggered on-site potential, the system could exhibit the quantum anomalous Hall and quantum spin Hall effects in the absence of a net magnetization. Besides the chiral edge states, these topological phases support a staggered Edelstein effect through which an applied electric field can generate opposite non-equilibrium spins on the two AFM sublattices, realizing the Néel-type spin-orbit torque (NSOT). Contrary to known NSOTs in AFM metals driven by conduction currents, our NSOT arises from pure adiabatic currents devoid of Joule heating, while being a bulk effect not carried by the edge currents. By virtue of the NSOT, the electric field of a microwave can drive the AFM dynamics with a remarkably high efficiency. Compared to the ordinary AFM resonance driven by the magnetic field, the new mechanism can enhance the resonance amplitude by more than one order of magnitude and the absorption rate of the microwave power by over two orders of magnitude. Our findings unravel an incredible way to exploit AFM topological phases to achieve ultrafast magnetic dynamics.
title Néel Spin-Orbit Torque in Antiferromagnetic Quantum Spin and Anomalous Hall Insulators
topic Mesoscale and Nanoscale Physics
Materials Science
Quantum Physics
url https://arxiv.org/abs/2410.21751