Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn2Au Probed by Time-Domain THz Spectroscopy

Bhattacharjee N, Sapozhnik AA, Bodnar SY, Grigorev VY, Agustsson SY, Cao J, Dominko D, Obergfell M, Gomonay O, Sinova J, Klaui M, Elmers HJ, Jourdan M, Demsar J (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Physical Review Letters American Physical Society

Book Volume: 120

Article Number: 237201

Journal Issue: 23

DOI: 10.1103/PhysRevLett.120.237201

Abstract

We observe the excitation of collective modes in the terahertz (THz) range driven by the recently discovered Néel spin-orbit torques (NSOTs) in the metallic antiferromagnet Mn2Au. Temperature-dependent THz spectroscopy reveals a strong absorption mode centered near 1 THz, which upon heating from 4 to 450 K softens and loses intensity. A comparison with the estimated eigenmode frequencies implies that the observed mode is an in-plane antiferromagnetic resonance (AFMR). The AFMR absorption strength exceeds those found in antiferromagnetic insulators, driven by the magnetic field of the THz radiation, by 3 orders of magnitude. Based on this and the agreement with our theory modeling, we infer that the driving mechanism for the observed mode is the current-induced NSOT. Here the electric field component of the THz pulse drives an ac current in the metal, which subsequently drives the AFMR. This electric manipulation of the Néel order parameter at high frequencies makes Mn2Au a prime candidate for antiferromagnetic ultrafast memory applications.

Involved external institutions

Johannes Gutenberg-Universität Mainz (JGU) DE Germany (DE)

How to cite

APA:

Bhattacharjee, N., Sapozhnik, A.A., Bodnar, S.Y., Grigorev, V.Y., Agustsson, S.Y., Cao, J.,... Demsar, J. (2018). Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn2Au Probed by Time-Domain THz Spectroscopy. Physical Review Letters, 120(23). https://doi.org/10.1103/PhysRevLett.120.237201

MLA:

Bhattacharjee, N., et al. "Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn2Au Probed by Time-Domain THz Spectroscopy." Physical Review Letters 120.23 (2018).

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