Martin Dressel

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Studies of the electromagnetic response of various classes of correlated electron materials including transition-metal oxides, organic and molecular conductors, intermetallic compounds with d and f electrons, as well as magnetic semiconductors are reviewed. Optical inquiry into correlations in all these diverse systems is enabled by experimental access to(More)
We describe the electronic control of extraordinary terahertz transmission through subwavelength metal hole arrays fabricated on doped semiconductor substrates. The hybrid metal-semiconductor forms a Schot-tky diode structure, where the active depletion region modifies the substrate conductivity in real-time by applying an external voltage bias. This(More)
Low-dimensional organic conductors could establish themselves as model systems for the investigation of the physics in reduced dimensions. In the metallic state of a one-dimensional solid, Fermi liquid theory breaks down and spin and charge degrees of freedom become separated. But the metallic phase is not stable in one dimension: as the temperature is(More)
In commemoration of Paul Drude (1863–1906) By now more than 100 years passed since Paul Drude suggested his highly acclaimed model of electronic transport. In the form advanced by A. Sommerfeld, the Drude model is still heavily utilized to describe, for instance, the optical properties of metals. Surprisingly, the key prediction of the Drude model, the(More)
The electrical conduction of metals is governed by how freely mobile electrons can move throughout the material. This movement is hampered by scattering with other electrons, as well as with impurities or thermal excitations (phonons). Experimentally, the scattering processes of single electrons are not observed, but rather the overall response of all(More)
Controlling the dynamics of spins on surfaces is pivotal to the design of spintronic and quantum computing devices. Proposed schemes involve the interaction of spins with graphene to enable surface-state spintronics and electrical spin manipulation. However, the influence of the graphene environment on the spin systems has yet to be unravelled. Here we(More)
  • María Dörfel, Michal Kern, Heiko Bamberger, Petr Neugebauer, Katharina Bader, Raphael Marx +8 others
  • 2016
The method of choice for in-depth investigation of the magnetic anisotropy in molecular nanomagnets is high-frequency electron spin resonance (HFESR) spectroscopy. It has the benefits of high resolution and facile access to large energy splittings. However, the sensitivity is limited to about 10 7 spins for a reasonable data acquisition time. In contrast,(More)
As the dimensionality is reduced, the world becomes more and more interesting ; novel and fascinating phenomena show up which call for understanding. Physics in one dimension is a fascinating topic for theory and experiment: for the former often a simplification, for the latter always a challenge. Various ways will be demonstrated how one-dimensional(More)
At low energy scales charge transport in the insulating Si:P is dominated by activated hopping between the localized donor electron states. Thus, theoretical models for a disordered system with electron-electron interaction are appropriate to interpret the electric conductivity spectra. With a newly developed technique we have measured the complex broadband(More)