206 citations · 481 across the 23 of their papers we have counts for
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Coherent Electron Optics with Ballistically Coupled Quantum Point Contacts
Jaan Freudenfeld, Max Geier, Vladimir Umansky +2
The realization of integrated quantum circuits requires precise on-chip control of charge carriers. Aiming at the coherent coupling of distant nanostructures at zero magnetic field…
Electrostatic potential shape of gate defined quantum point contacts
Max Geier, Jaan Freudenfeld, Jorge T. Silva +5
Quantum point contacts (QPC) are fundamental building blocks of nanoelectronic circuits. For their emission dynamics as well as for interaction effects such as the 0.7-anomaly the…
Optimization of ohmic contacts to n-type GaAs nanowires
Ludwig Hüttenhofer, Dionysios Xydias, Ryan B. Lewis +6
III-V nanowires are comprehensively studied because of their suitability for optoelectronic quantum technology applications. However, their small dimensions and the spatial separat…
Field effect induced mesoscopic devices in depleted two dimensional electron systems
N. Bachsoliani, S. Platonov, A. D. Wieck +1
Nanoelectronic devices embedded in the two-dimensional electron system (2DES) of a GaAs/AlGaAs heterostructure enable a large variety of applications from fundamental research to h…
Multistability and spin diffusion enhanced lifetimes in dynamic nuclear polarization in a double quantum dot
Florian Forster, Max Mühlbacher, Dieter Schuh +3
The control of nuclear spins in quantum dots is essential to explore their many-body dynamics and exploit their prospects for quantum information processing. We present a unique co…
Lissajous rocking ratchet
S. Platonov, B. Kästner, H. W. Schumacher +2
Breaking time-reversal symmetry (TRS) in the absence of a net bias can give rise to directed steady-state non-equilibrium transport phenomena such as ratchet effects. Here we prese…
Towards combined transport and optical studies of the 0.7-anomaly in a quantum point contact
E. Schubert, J. Heyder, F. Bauer +5
A Quantum Point Contact (QPC) causes a one-dimensional constriction on the spatial potential landscape of a two-dimensional electron system. By tuning the voltage applied on a QPC…
Tunable non-equilibrium Luttinger liquid based on counter-propagating edge channels
M. G. Prokudina, S. Ludwig, V. Pellegrini +3
We investigate energy transfer between counter-propagating quantum Hall edge channels (ECs) in a two-dimensional electron system at filling factor ν=1. The ECs are separated by a t…
Anomalous resistance overshoot in the integer quantum Hall effect
E. M. Kendirlik, S. Sirt, S. B. Kalkan +4
In this work we report experiments on defined by shallow etching narrow Hall bars. The magneto-transport properties of intermediate mobility two-dimensional electron systems are in…
Large nuclear spin polarization in gate-defined quantum dots using a single-domain nanomagnet
Gunnar Petersen, Eric A. Hoffmann, Dieter Schuh +3
The electron-nuclei (hyperfine) interaction is central to spin qubits in solid state systems. It can be a severe decoherence source but also allows dynamic access to the nuclear sp…
Few electron double quantum dot in an isotopically purified Si quantum well
Andreas Wild, Johannes Kierig, Jürgen Sailer +5
We present a few electron double quantum dot (QD) device defined in an isotopically purified Si quantum well (QW). An electron mobility of is…
An electron jet pump: The Venturi effect of a Fermi liquid
D. Taubert, G. J. Schinner, C. Tomaras +3
A three-terminal device based on a two-dimensional electron system is investigated in the regime of non-equilibrium transport. Excited electrons scatter with the cold Fermi sea and…
Nonequilibrium phenomena in adjacent electrically isolated nanostructures
V. S. Khrapai, S. Ludwig, J. P. Kotthaus +2
We report on nonequilibrium interaction phenomena between adjacent but electrostatically separated nanostructures in GaAs. A current flowing in one externally biased nanostructure…
Telegraph Noise in Coupled Quantum Dot Circuits Induced by a Quantum Point Contact
D. Taubert, M. Pioro-Ladrière, D. Schröer +3
Charge detection utilizing a highly biased quantum point contact has become the most effective probe for studying few electron quantum dot circuits. Measurements on double and trip…
An electrostatically defined serial triple quantum dot charged with few electrons
D. Schröer, A. D. Greentree, L. Gaudreau +4
A serial triple quantum dot (TQD) electrostatically defined in a GaAs/AlGaAs heterostructure is characterized by using a nearby quantum point contact as charge detector. Ground sta…
A widely tunable few electron droplet
A. K. Huettel, K. Eberl, S. Ludwig
Quasi-static transport measurements are employed to characterize a few electron quantum dot electrostatically defined in a GaAs/AlGaAs heterostructure. The gate geometry allows obs…
Kondo effect in a one-electron double quantum dot: Oscillations of the Kondo current in a weak magnetic field
D. M. Schröer, A. K. Hüttel, K. Eberl +3
We present transport measurements of the Kondo effect in a double quantum dot charged with only one or two electrons, respectively. For the one electron case we observe a surprisin…
Molecular states in a one-electron double quantum dot
A. K. Huettel, S. Ludwig, H. Lorenz +2
The transport spectrum of a strongly tunnel-coupled one-electron double quantum dot electrostatically defined in a GaAs/AlGaAs heterostructure is studied. At finite source-drain-vo…