Stefan Ludwig
YOU?
Author Swipe
View article: Nature of current flow in the regime of the quantum Hall effect
Nature of current flow in the regime of the quantum Hall effect Open
The integer quantum Hall effect (QHE) belongs to the most fundamental phenomena of solid state physics and has an important application as resistance standard. It serves as a basis to understand the fractional, anomalous or spin QHEs, cand…
View article: Transition from edge- to bulk-currents in the quantum Hall regime
Transition from edge- to bulk-currents in the quantum Hall regime Open
The integer quantum Hall effect can be observed in a two-dimensional conductor penetrated by a perpendicular magnetic field and with edges connecting the current carrying contacts. Its signature is a state of quantized Hall and simultaneou…
View article: Current density distribution for the quantum Hall effect
Current density distribution for the quantum Hall effect Open
Our microscopic understanding of the integer quantum Hall effect is still incomplete. For decades, there has been a controversial discussion about "where the current flows" if the Hall resistance is quantized. Here, we qualitatively analyz…
View article: Nature of current flow in the regime of the quantum Hall effect
Nature of current flow in the regime of the quantum Hall effect Open
The integer quantum Hall effect (QHE) belongs to the most fundamental phenomena of solid state physics and has an important application as resistance standard. It serves as a basis to understand the fractional, anomalous or spin QHEs, cand…
View article: Transition from edge- to bulk-currents in the quantum Hall regime
Transition from edge- to bulk-currents in the quantum Hall regime Open
The integer quantum Hall effect can be observed in a two-dimensional conductor penetrated by a perpendicular magnetic field and with edges connecting the current carrying contacts. Its signature is a state of quantized Hall and simultaneou…
View article: Publisher Correction: Classical analogue to driven quantum bits based on macroscopic pendula
Publisher Correction: Classical analogue to driven quantum bits based on macroscopic pendula Open
View article: Classical analogue to driven quantum bits based on macroscopic pendula
Classical analogue to driven quantum bits based on macroscopic pendula Open
View article: Akute mesenteriale Durchblutungsstörung
Akute mesenteriale Durchblutungsstörung Open
View article: Determining Amplitudes of Standing Surface Acoustic Waves via Atomic Force Microscopy
Determining Amplitudes of Standing Surface Acoustic Waves via Atomic Force Microscopy Open
Atomic force microscopy is an important tool for characterizing surface\nacoustic waves, in particular for high frequencies, where the wavelength is too\nshort to be resolved by laser interferometry. A caveat is, that the cantilever\ndefle…
View article: Atomic force microscopy calibration of standing surface acoustic wave amplitudes
Atomic force microscopy calibration of standing surface acoustic wave amplitudes Open
Atomic force microscopy is an important tool for characterizing surface acoustic waves, in particular for high frequencies, where the wavelength is too short to be resolved by laser interferometry. A caveat is, that the cantilever deflecti…
View article: Coherent Electron Optics with Ballistically Coupled Quantum Point Contacts
Coherent Electron Optics with Ballistically Coupled Quantum Point Contacts Open
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, here we study the ballistic electron transport through tw…
View article: Electrostatic potential shape of gate-defined quantum point contacts
Electrostatic potential shape of gate-defined quantum point contacts Open
Quantum point contacts (QPCs) are fundamental building blocks of nanoelectronic circuits. For their emission dynamics as well as for interaction effects such as the 0.7 anomaly the details of the electrostatic potential are important, but …
View article: Landau-Zener interference at bichromatic driving
Landau-Zener interference at bichromatic driving Open
We investigate experimentally and theoretically the interference at avoided crossings which are repeatedly traversed as a consequence of an applied ac field. Our model system is a charge qubit in a serial double quantum dot connected to tw…
View article: Multistability and spin diffusion enhanced lifetimes in dynamic nuclear polarization in a double quantum dot
Multistability and spin diffusion enhanced lifetimes in dynamic nuclear polarization in a double quantum dot Open
The control of nuclear spins in quantum dots is essential to explore their\nmany-body dynamics and exploit their prospects for quantum information\nprocessing. We present a unique combination of dynamic nuclear spin\npolarization and elect…
View article: Relation between the 0.7 anomaly and the Kondo effect: Geometric crossover between a quantum point contact and a Kondo quantum dot
Relation between the 0.7 anomaly and the Kondo effect: Geometric crossover between a quantum point contact and a Kondo quantum dot Open
Quantum point contacts (QPCs) and quantum dots (QDs), two elementary building\nblocks of semiconducting nanodevices, both exhibit famously anomalous\nconductance features: the 0.7-anomaly in the former case, the Kondo effect in\nthe latter…
View article: Lissajous Rocking Ratchet: Realization in a Semiconductor Quantum Dot
Lissajous Rocking Ratchet: Realization in a Semiconductor Quantum Dot Open
Breaking time-reversal symmetry (TRS) in the absence of a net bias can give rise to directed steady-state nonequilibrium transport phenomena such as ratchet effects. Here we present, theoretically and experimentally, the concept of a Lissa…
View article: Multiple fixed points of dynamically polarized nuclear spins in a double quantum dot
Multiple fixed points of dynamically polarized nuclear spins in a double quantum dot Open
Dynamic nuclear spin polarization (DNSP) and electric-dipole-induced spin resonance (EDSR) are major tools to control the nuclear and electron spin dynamics in semiconductor nanostructures. Their local control can be massively enhanced in …
View article: Electric-dipole-induced spin resonance in a lateral double quantum dot incorporating two single-domain nanomagnets
Electric-dipole-induced spin resonance in a lateral double quantum dot incorporating two single-domain nanomagnets Open
On-chip magnets can be used to implement relatively large local magnetic\nfield gradients in na- noelectronic circuits. Such field gradients provide\npossibilities for all-electrical control of electron spin-qubits where\nimportant couplin…