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Impact of current-induced magnons on spin-orbit-torque analysis

Tamás Prok1,2,3, Jan Hidding3, Szabolcs Csonka1,4,5, Péter Makk1,2, Marcos H.D. Guimarães3, and Endre Tóvári1,2,*

  • 1Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rakpart 3., 1111 Budapest, Hungary
  • 2MTA-BME Correlated van der Waals Structures Momentum Research Group, Műegyetem rakpart 3., 1111 Budapest, Hungary
  • 3Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
  • 4MTA-BME Superconducting Nanoelectronics Momentum Research Group, Műegyetem rakpart 3., 1111 Budapest, Hungary
  • 5HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly Thege Miklós út 29–33, 1121 Budapest, Hungary

  • *Contact author: tovari.endre@ttk.bme.hu
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Phys. Rev. Applied 25, 064018 – Published 4 June, 2026

DOI: https://doi.org/10.1103/x78x-qt5z

Abstract

The second-harmonic Hall technique is a widely used, sensitive method for studying the spin-orbit torques generated by charge current. It exploits the dependence of the Hall resistance on the magnetization direction, although thermal phenomena also contribute. Historically, deviations from the expected magnetic field dependence have usually been ignored. On the basis of our studies on permalloy/platinum bilayers, we show that a counterpart to the magnon-related spin-flip unidirectional magnetoresistance—known to appear in the second-harmonic longitudinal resistance—appears in the Hall data, and that describing the results in a wide field range with these contributions is essential to accurately estimate the torques.

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Phys. Rev. Applied 25, 064018– Published 4 June, 2026
  • Received 24 April 2025
  • Revised 2 February 2026
  • Accepted 14 April 2026
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