Candidato de prueba
Research project
Toward terahertz orbital pumping in ferromagnet/non-magnet stacks
Project supervisor
Tobias Kampfrath
Recruitment date
13/03/2026
Project Description
The reliable generation and detection of currents of electronic orbital momentum (L) and spin angular momentum (S) are of central importance in future spin-orbitronic devices. Importantly, many of the fundamental processes governing the transport of L, S and electronic charge proceed on femtosecond (fs) time scales and, thus, at terahertz (THz) frequencies. Examples include the relaxation of the linear momentum, energy and spin of electrons. Therefore, it is essential to study the dynamics of S and L on the fs and THz scales.
In this project, we will investigate ultrafast L and S transport in prototypical ferromagnet/non-magnet (FM/NM) thin-film stacks consisting of a ferromagnetic-metal layer FM and a nonmagnetic-metal layer NM. To trigger and detect L and S currents, we will make use of a cutting-edge ultrafast L/S amperemeter whose operation strongly relies on fs laser pulses and THz electromagnetic pulses. One focus of the project will lie on the differentiation of coherent and incoherent transport of L and S.
Host institution
Freie Universität Berlin is among the select few German institutions of higher education supported by the German federal and state governments’ Excellence Strategy. The Department of Physics has a strong, longstanding and successful research focus on ultrafast dynamics in condensed matter. It is part of a recently established and selected Excellence Cluster, the Center for Chiral Electronics.
The work group Terahertz Physics of Quantum Materials aims to push spin-orbitronic effects from the quasi-DC to the terahertz (THz) frequency range, on one hand, to dissect the initial microscopic steps of these effects, on the other hand, to explore possible applications in THz photonics. Accomplishments are the development and understanding of spintronic sources and detectors of broadband THz radiation and the demonstration of THz Néel spin-orbit torque in antiferromagnets.
Planned Secondments
Academic Secondment
CEA
Paris-Saclay, France
Michel Viret
Industrial Secondment
THALES
Palaiseau, France
Dr. Romain Lebrun
Registering University
Freie Universität Berlin
Germany