ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarUlrich NowakUniversity of Konstanz (host: Rózsa Levente)The role 
of angular momentum in ultrafast spintronicsWednesday, 10 April 2024, 10:00, 
KFKI Campus, Bldg. 1, 2nd floor, Conference RoomStarting with the famous 
discovery of Einstein and De Haas, it has been common knowledge that magnetic 
moment and angular momentum are physical properties which are fundamentally 
connected. As a consequence, electrodynamics is coupled to quantum mechanics 
and the transfer and control of angular momentum is a key aspect for the 
understanding of magnetic materials and the development of future spintronic 
applications.As a further consequence, precession dominates magnetization 
dynamics in analogy to the mechanical motion of a spinning top. When a 
ferromagnetic film is excited by strong, ultrashort laser pulses, it can lose 
its magnetic order almost completely on femtosecond time scales. Only 
recently we could demonstrate that, on the same time scale, the spin angular 
momentum is transferred to the lattice via the ultrafast creation of chiral 
phonons that absorb the angular momentum of the spin system [1].In this talk, 
I will focus on the dynamics of spin angular momentum and on the development 
of a framework for the simulation of coupled spin-lattice dynamics. 
Furthermore, I will show how magnetic inertia can separate the dynamics of 
the magnetization from its angular momentum, an effect that in mechanics is 
known as nutation.[1] S. R. Tauchert et al., Nature 602, 73 
(2022). Minden érdeklődőt szívesen látunk! - Everyone is welcome to 
attend.Attila Nagysem-admin AT szfki.hu