Soliton Dynamics in monoaxial chiral magnets

Engineering and/or Technology, Mathematics and/or Informatics, Natural Sciences
Spain
Zaragoza
Period: 
1 Jan, 2021 to 31 Dec, 2021
Deadline: 
31 Aug, 2020

General information

Duration: 
6 months
Commitment: 
Full-time
Description: 

The chiral solitons stabilized by the DMI are very interesting because they can present advantages over skyrmions, since their movement is not gyro-tropic and they will be easier to control. Moreover, it is interesting to elucidate the advantages that they can present with respect to the domain walls.
On the other hand, the theoretical techniques used to study the dynamics of magnetic structures are of two types: i) the introduction of a few collective variables to describe the structure and ii) the numerical resolution of the LLG equation. In the first case, a generalization of the method of collective variables recently developed is used, and it will be necessary to deduce the equations that govern the dynamics of collective variables. For linear structures such as domain walls and chiral solitons in two dimensions (thin films) the center of the structure forms a line and its dynamics can be described by an elastic line model. The rest of the collective variables (for example, the width) could qualitatively change the dynamics of the elastic line.

Objectives
Main objective is the study of the response of solitons in monoaxial chiral magnets to applied magnetic fields and spin transfer torques induced by polarized electric currents, by means of effective models of collective variables and numerical simulations of the Landau-Lifshitz-Gilbert equation (LLG)

Mainly numerical techniques will be used, although it will also be necessary to apply analytical techniques. In particular, numerical resolution techniques of initial value problems will be used in deterministic and stochastic differential equations (explicit or implicit methods) and border value problems (relaxation methods). The analytical techniques will be of a perturbative nature and will be applied to cases where external forces are weak.

Compensation: 
Financial compensation
Health Insurance
Years of Experience required: 
No

Keywords

magnetism  magnonics  magnetic chirality  magnetic solitons  theory of condensed matter  

Additional Information

The work plan will be developed within the Multifunctional Molecular Magnetic Materials Group of the Institute of Materials Science of Aragon, which has extensive experience in the study of chiral magnetism, both experimentally and theoretically. In particular, he has extensive experience in computing applied to fields as diverse as magnetism, statistical mechanics, and thermal neutron propagation. It also has its own software for solving initial value problems and border value problems applied to magnetism, which can be used as a starting point for the developments proposed in this project. The group has its own computing resources and access to those of the University of Zaragoza and those of the CSIC. If necessary, computing time can also be requested in the MareNostrum supercomputer
Requirements
Languages: 
English: Independent User B2
Spanish: Independent User B2
Level of Studies: 
Master