Seminar experimentelle Physik der kondensierten Materie

Programm für das Sommersemester 2022

Thursdays, 14:00 Uhr s.t.

01-122 Newton Raum

13.06.22Markus Ternes, RWTH Aachen
16:00 Uhr s.t., TUK, 46/HS270, at Zoom

Zoom ID: 699 4140 4654 with Passcode: PhyKo#2022

20.06.22Sebastian Loth, University of Stuttgart
16:00 Uhr s.t., TUK 46/HS 270, at Zoom

Zoom ID: 699 4140 4654 and Passcode: PhyKo#2022

01.07.22Julian Skolaut, KIT, Germany
There has been a longstanding interest in the realization of machines, such as motors, on the nanoscale. First described in a thought experiment by Marian Smoluchowski in 1912 and popularized by Richard Feynman in 1962, the concept of the so-called Brownian ratchet has shown the physical limits in the realization of such nanomachines. Long after the theoretical description of such nanomachines, Bernard L. Feringa was able to design and synthesize a light-driven molecular motor and was awarded the Nobel Prize in 2016. Taking a different approach by using the electric current in a scanning tunneling microscope (STM) as the stimulus, we present our results concerning a single molecular motor. Three anchoring groups fix the molecules to a Au(111) surface. The chiral functional group is connected via a rotatable axis and is supposed to perform a rotation in a preferred direction, proposed to be driven based on the chiral-induced spin selectivity (CISS) effect. This effect causes the electron spin of an injected current to be spin-polarized after passing through a chiral electric field, exerting a torque on the functional group via spin-orbit coupling. Indeed, when positioning the STM tip above the molecule at a fixed position, we can observe directed rotation in the follwing way : We observe three distinguishable current levels, which are interpreted as metastable rotational states of the molecule. That way, two rotation directions can be defined. Via binomial tests, we verify that the surplus of rotational switches in one direction compared to the other is statistically significant. In voltage and current dependent measurements, two interesting trends are observed. The rate of events decreases with increasing current and the asymmetry in the switching events varies non-monotonically with voltage. From voltage polarity dependent measurements, it is possible to extract more information on the underlying effect causing the directed rotation.
10:00 Uhr s.t., Medienraum 03-431, institute of Physics

30.08.22Elizaveta Tremsina, MIT, USA
Atomistic Simulations of Distortion-limited High-speed Dynamics of Antiferromagnetic Skyrmions
10:30 Uhr s.t., THEP Seminar Room 05-427, at Zoom

31.08.22Aurélien Manchon, Aix-Marseille University, France
Exploring the potentials of spin-orbitronics
9:30 Uhr s.t., 03-431, Medienraum, Staudingerweg 7

01.09.22Jingsheng Chen, National University of Singapore
Symmetry Breaking by Materials Engineering for Spin-Orbit-Torque Technology
14:00 Uhr s.t., 01-122 Newton Raum, at Zoom

12.09.22Xin Fan, University of Denver
Transversely-Polarized Spin Current Generation from Ferromagnetic Metals
11:00 Uhr s.t., Kaiserslautern building 46/270, at Zoom


Univ-Prof. Dr. Jure Demsar
Univ.-Prof. Dr. Hans-Joachim Elmers
Univ.-Prof. Dr. Mathias Kläui
Univ.-Prof. Dr. Thomas Palberg