Kolloquien  |  Physik

SFB 767 Colloquium: Dynamical spin excitations in nanoscale magnets: from single adatoms to skyrmions

Wann
Donnerstag, 22. Juni 2017
15.15 – 16.45 Uhr

Wo
P 603

Veranstalter
SFB 767 / Fabian Pauly, 3865

ReferentIn:
Jun.-Prof. Samir Lounis, Peter-Grünberg-Institut and Institute for Advanced Simulation, Forschungszentrum Jülich & JARA

Dynamical spin excitations in nanoscale magnets: from single adatoms to skyrmions

Stabilising, probing and manipulating the magnetic signal of single adatoms are crucial toward their successful usage in widespread technological applications such as high-density magnetic data storage devices. Ultimately a single magnetic atom is the smallest magnetic bit of information, thus the great interest in grasping its excitation behavior pertaining to any writing or reading process. I will present an overview of our investigations for different atoms deposited on several substrates. Combining time-dependent density functional theory and many-body perturbation theory, we showed that current-driven spin-state manipulation in nano-devices leads to rich transport patterns with new many-body features, resulting from the interaction of the electrons and the spin-excitations detectable with state of the art inelastic scanning tunneling spectroscopy. The intricate interplay between the intra- and interatomic exchange interactions and the spin-orbit interaction dramatically modify the dynamical behaviour of the nanomagnets and the lifetime of the newly produced magnetic state. Furthermore, I will address zero-point spin-fluctuations leading to a collapse of the magnetic anisotropy energy barrier even at absolute zero temperature and I will provide practical guidelines for designing magnetically stable nanomagnets with minimal quantum fluctuations. If I have time, I will briefly discuss our planned investigations on dynamical spin-excitations in large magnetic objects such as skyrmions containing hundreds of atoms.