Victor Iwanaga

Research project

Toward terahertz orbital pumping in ferromagnet/non-magnet stacks

Project supervisor

Tobias Kampfrath

Recruitment date

07/10/2026

Hello everyone, my name is Victor.

Born and raised in Berlin, I studied ultrafast demagnetization of ferromagnets during my bachelor's degree at the Technical University of Berlin. Then, I decided to move halfway across the world to join a master's program at Tohoku University in Japan. Here, I am currently studying Terahertz (THz) waves, and I am very lucky to be included in many projects, such as approaches for generating structured light and developing novel, broadband THz waveplates.

Within the ORBIS project, I wish to apply my background in magnetism and THz waves to study the dynamics of electronic orbital and spin angular momentum in ferromagnetic/non-magnetic stacks excited at THz frequencies.

Outside the lab, I have recently developed a passion for surfing. With the exact same enthusiasm I have for measuring THz waves in the laboratory, I now enjoy catching water waves in the ocean. Besides surfing, I am also always up for some competitive games of table tennis!

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