IRP10
theoretical project
Microscopic origin and optimization of the orbital Hall effect
Location
Halle, Germany
Host institution
Martin Luther Universität Halle-Wittenberg (MLU) is a reference German university. As the biggest university in the state of Saxony-Anhalt, MLU cooperates with more than 200 institutions of higher education from around the world in study programmes and joint research projects.
The Quantum theory of Solid State group of the Institute of Physics started its activities in 2001, doing basic research in the field of solid state theory. Its main focus is the microscopic understanding of the electronic, magnetic, ferroelectric, and transport properties on the atomic scale. Research is dedicated to the emerging phenomena in the fields of spintronics, spinorbitronics, and orbitronics.
Supervisor
Prof. Ingrid Mertig
Description
n orbital current can be generated whenever an object has a translational and a rotational degree of freedom. The OHE is caused by an intra-atomic contribution related to orbital motion of the electrons in hybridized orbitals. However, interatomic contributions must be considered as well because they give rise to an alternative mechanism for generating orbital currents. Even wave packets consisting purely of s electrons can transport OAM if they move on a cycloidal trajectory. This motion is particularly related to edge states. In principle, the OHE can generate currents of angular momentum more efficiently than the SHE in most metals. However, so far, it has only been described as a steady-state phenomenon. In this IRP, the OHE is extended into the time domain. OAM and their currents induced by a femtosecond laser pulse will be calculated. The numerical simulations provide detailed insights into the laser-driven electron dynamics on ultrashort timescales with atomic resolution. The ultrafast OHE is consistent with the familiar pictorial representation of the static OHE with pronounced differences between physical quantities that carry OAM and those that carry charge. DC10 will consider certain scenarios of sample modification (impurities, edges, heterostructures) to optimize the effect. Although the OAM is not conserved, we will check whether conservation of partial components is valid at interfaces. A very important question must be addressed how an orbital current can be converted into a charge current.
Requirements
- Master of Science in Physics
- Preferred : experience in computational physics
- Preferred : experience in Solid State Theory and Transport Theory
Planned Secondments
- Academic secondment at Centre Interdisciplinaire de Nanoscience de Marseille (CNRS-CINaM), under the supervision of Aurélien Manchon
- Industrial secondment at MPhysX OÜ, under the supervision of Thierry Valet
Planned Secondments
Academic Secondment
Centre Interdisciplinaire de Nanoscience de Marseille (CNRS-CINaM)
Aix-Marseille, France
Aurélien Manchon
Industrial Secondment
MPhysX OÜ
Tallinn, Estonia
Thierry Valet
Registering University
Martin Luther Universität Halle-Wittenberg
