Publications (11)
Donor implanted Back-gates in GaAs for MBE-grown highest mobility two-dimensional electron systems
Jan Scharnetzky, Philipp Baumann, Christian Reichl +3
Three different elements, Silicon, Selenium, and Tellurium, are ion-implanted in Gallium arsenide to form a conducting layer that serves as a back-gate to a molecular beam epitaxy…
Site-selective ion beam synthesis and optical properties of individual CdSe nanocrystal quantum dots in a SiO2 matrix
H. Moritz Mangold, Helmut Karl, Hubert J. Krenner
Cadmium selenide nanocrystal quantum dots (NC-QDs) are site-selectively synthesized by sequential ion beam implantation of selenium and cadmium ions in a SiO2 matrix through sub-mi…
Ultrafast photocurrents and THz generation in single InAs-nanowires
Nadine Erhard, Paul Seifert, Leonhard Prechtel +5
To clarify the ultrafast temporal interplay of the different photocurrent mechanisms occurring in single InAs-nanowire-based circuits, an on-chip photocurrent pump-probe spectrosco…
VO2 Nanocrystals for Designer Phase-Change Metamaterials
Jimmy John, Yael Gutierrez, Zhen Zhang +5
Subwavelength nanoparticles can support electromagnetic resonances with distinct features depending on their size, shape and nature. For example, electric and magnetic Mie resonanc…
Ultrafast helicity control of surface currents in topological insulators with near-unity fidelity
Christoph Kastl, Christoph Karnetzky, Helmut Karl +1
In recent years, a class of solid state materials, called three-dimensional topological insulators, has emerged. In the bulk, a topological insulator behaves like an ordinary insul…
Structured Back Gates for High-Mobility Two-Dimensional Electron Systems Using Oxygen Ion Implantation
Matthias Berl, Lars Tiemann, Werner Dietsche +2
We present a new approach of back gate patterning that is compatible with the requirements of highest mobility molecular beam epitaxy. Contrary to common back gating techniques, ou…
THz-circuits driven by photo-thermoelectric graphene-junctions
Andreas Brenneis, Felix Schade, Simon Drieschner +4
For future on-chip communication schemes, it is essential to integrate nanoscale materials with an ultrafast optoelectronic functionality into high-frequency circuits. The atomical…
Ion beam synthesis of nanothermochromic diffraction gratings with giant switching contrast at telecom wavelengths
Johannes Zimmer, Achim Wixforth, Helmut Karl +1
Nanothermochromic diffraction gratings based on the metal-insulator transition of are fabricated by site-selective ion beam implantation in a matri…
Hematite Thin Films Grown on Z-Cut and Y-Cut Lithium Niobate Piezoelectric Substrates by Pulsed Laser Deposition
Maximilian Mihm, Stephan Glamsch, Christian Holzmann +3
Altermagnets are a newly identified class of materials that combine advantageous characteristics of both ferro- and antiferromagnets, making them highly promising for spintronic ap…
Ultrafast photodetection in the quantum wells of single AlGaAs/GaAs-based nanowires
Nadine Erhard, Stefan Zenger, Stefanie Morkötter +8
We investigate the ultrafast optoelectronic properties of single Al0.3Ga0.7As/GaAs-core-shell-nanowires. The nanowires contain GaAs-based quantum wells. For a resonant excitation o…
Ultrafast electronic read-out of diamond NV centers coupled to graphene
Andreas Brenneis, Louis Gaudreau, Max Seifert +6
Nonradiative transfer processes are often regarded as loss channels for an optical emitter1, since they are inherently difficult to be experimentally accessed. Recently, it has bee…