Topology and magnonic transport in fluctuating magnetic nanostructures

Nyomtatóbarát változatNyomtatóbarát változat
Doctoral school: 
Fizikai Tudományok Doktori Iskola
Year/Semester: 
2023/2024/1
Supervisor
Name: 
Levente Rózsa
Email: 
rozsa.levente@wigner.hu
Institute: 
Wigner Research Centre for Physics (WIGNER FK)
Job title: 
senior research fellow
Academic degree: 
PhD
Consulant
Name: 
László Szunyogh
Email: 
szunyogh.laszlo@ttk.bme.hu
Institute: 
Department of Theoretical Physics
Job title: 
professor
Academic degree: 
doctor of the Hungarian Academy of Sciences
Description: 

Exotic magnetic configurations are stabilized in solids at the nanoscale, in which the magnetic moment direction considerably varies between neighbouring atoms. These structures, including so-called skyrmions and hopfions, can be treated as quasiparticles since they are robust against perturbations. They can be characterized by topological invariants which are reflected in their unique transport properties, for example during their interaction with spin currents carried by magnon excitations in magnetic insulators. Their high stability and special transport signatures make these quasiparticles promising candidates for storing information in energy-efficient memory and logic devices. Skyrmions have been proposed to be used in unconventional computing architectures as well, including neuromorphic and stochastic computing, which offer a more fault-tolerant operation where the stability of individual quasiparticles is less crucial. In the proposed doctoral project, numerical simulations and analytical models will be applied to reveal the connection between the topology of the spin structure and transport phenomena at high temperatures, where the long-term stability is lost because the quasiparticles are frequently created and destroyed by thermal fluctuations. The research is to be carried out using a spin dynamics computer simulation code developed at the institute. It is planned to be explored how magnonic spin currents can be described in this high-temperature regime, and how the strongly fluctuating configurations influence these currents. The project will provide the opportunity for collaboration with other experimental and theoretical groups within an international network.

Requirements: 
Solid knowledge of quantum mechanics and solid-state physics, preferably with experience in the field of magnetism. Strong motivation for numerical simulation work and a background in scientific (Matlab or python) and general (C, C++ or Fortran) programming languages.
Status: 
Finalized/Végleges