Magnetic Bloch oscillations and domain wall dynamics in a near-Ising ferromagnetic chain

• Published in: Nature communications Vol. 13; no. 1; pp. 2547 - 8
• Main Authors: Hansen, Ursula B., Syljuåsen, Olav F., Jensen, Jens, Schäffer, Turi K., Andersen, Christopher R., Boehm, Martin, Rodriguez-Rivera, Jose A., Christensen, Niels B., Lefmann, Kim
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.05.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/2793; 639/766/119/997; 639/766/483/1139; Chains; Charged particles; Domain walls; Electric fields; Electron spin; Excitation spectra; Ferromagnetism; Humanities and Social Sciences; Inelastic scattering; Ising model; Lattices; Magnetic domains; Magnetic fields; Magnetism; multidisciplinary; Neutron scattering; Neutrons; Oscillation modes; Oscillations; Particle physics; Science; Science (multidisciplinary); Spin dynamics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-29854-9

When charged particles in periodic lattices are subjected to a constant electric field, they respond by oscillating. Here we demonstrate that the magnetic analogue of these Bloch oscillations are realised in a ferromagnetic easy axis chain. In this case, the “particles” undergoing oscillatory motion in the presence of a magnetic field are domain walls. Inelastic neutron scattering reveals three distinct components of the low energy spin-dynamics including a signature Bloch oscillation mode. Using parameter-free theoretical calculations, we are able to account for all features in the excitation spectrum, thus providing detailed insights into the complex dynamics in spin-anisotropic chains. An electron subject to a periodic potential and a constant electric field exhibit oscillatory dynamics, known as Bloch oscillations. Here, the authors demonstrate a magnetic analogue of Bloch oscillations in a ferromagnetic near-Ising chain, where magnetic excitations oscillate in response to a magnetic field.