VSR-Seminar

Vortrag 1: Theoretical prediction for the muon magnetic moment

Referent: Prof. Kalman Szabo, JSC

In our multi-year project we are calculating the Standard Model prediction for the anomalous magnetic moment. An experimental measurement is expected early 2019, to which occasion a precise theory result is highly desirable. As a first step we made a full calculation with 2.6% total uncertainty. We are currently concentrating efforts to go below per-cent level accuracy.

Vortrag 2 Dynamical spin-orbitronics effects in magnetic systems

Referent: Dr. Filipe Guimaraes, IAS-1

The magnetization dynamics underlie any manipulation and detection of magnetic building blocks of future spintronic devices. In its core, two main ingredients define this dynamics: the driving field and the relaxation processes, which are profoundly connected to the coupling between orbital and spin degrees of freedom. Thus, for a deep understanding of the mechanisms present in realistic structures, we employ a microscopic material-specific dynamical theory based on a multi-orbital tight-binding model to developed a massively parallel code called TITAN (Time-dependent Transport and Angular momentum in Nanostructures). We use this unique approach to simulate and analise the different dynamical behavior of ferromagnetic and antiferromagnetic bilayers and trilayers, demonstrating how the resonances, reaching the THz range, can be excited by electrical means and how they may enhance the currents flowing through the system  [1,2]. Moreover, this framework was also used to examine several methods available to describe and compute the intrinsic damping mechanisms [3]. Our investigations unravel the dynamical contributions to many phenomena used in technological devices and build a solid foundation for future investigations of dynamical magnetic effects.

[1] F. S. M. Guimarães et al., Phys. Rev. B 92, 220410(R) (2015)
[2] F. S. M. Guimarães et al., Sci. Rep. 7, 3686 (2017)
[3] F. S. M. Guimarães et al., arXiv:1807.11808 [cond-mat.mes-hall]