Work

Dynamically generated spin interactions and nutational spin inertia in normal metal–ferromagnet heterostructures

Year: 2025

Type: article

Abstract: We consider the spin dynamics of a normal metal--ferromagnet heterostructure, with emphasis on spin-nutation terms arising from a dynamical Ruderman-Kittel-Kasuya-Yosida interaction. We find that the spin-nutation term is anisotropic in spin space due to the broken time-reversal symmetry of the ferromagnet. This contrasts with what one obtains in the paramagnetic state, where the nutation term is isotropic in spin space. We compute the effects this has on the magnetization dynamics derived from a Landau-Lifshitz-Gilbert equation. In particular, due to broken time-reversal symmetry, we predict a qualitative change in the zero-field ferromagnetic resonance spectrum which is present up to the Curie temperature. We propose that this is a strong indicator of the existence of nutation in ferromagnetically ordered spin systems.

Source: Physical review. B./Physical review. B

DOI: 10.1103/physrevb.111.144423

Authors: Christian Svingen Johnsen, Asle Sudbø

Institution: Norwegian University of Science and Technology

Language: English

Topic: Magnetic properties of thin films

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: European Cooperation in Science and Technology, Norges Forskningsråd

Awards: G1630594612, G2165927803, G423719072