0000000000025875

AUTHOR

C. Leicht

showing 3 related works from this author

Generation of energy selective excitations in quantum hall edge states

2011

We operate an on-demand source of single electrons in high perpendicular magnetic fields up to 30T, corresponding to a filling factor below 1/3. The device extracts and emits single charges at a tunable energy from and to a two-dimensional electron gas, brought into well defined integer and fractional quantum Hall (QH) states. It can therefore be used for sensitive electrical transport studies, e.g. of excitations and relaxation processes in QH edge states.

FOS: Physical sciences02 engineering and technologyElectronCorrelated Electron Systems / High Field Magnet Laboratory (HFML)Quantum Hall effect7. Clean energy01 natural sciences0103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)Materials ChemistryPerpendicularElectrical and Electronic EngineeringWell-defined010306 general physicsPhysicsCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed matter physicsFilling factorRelaxation (NMR)021001 nanoscience & nanotechnologyCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsMagnetic fieldComputingMethodologies_DOCUMENTANDTEXTPROCESSING0210 nano-technologyFermi gas
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Single-parameter quantized charge pumping in high magnetic fields

2008

We study single-parameter quantized charge pumping via a semiconductor quantum dot in high magnetic fields. The quantum dot is defined between two top gates in an AlGaAs/GaAs heterostructure. Application of an oscillating voltage to one of the gates leads to pumped current plateaus in the gate characteristic, corresponding to controlled transfer of integer multiples of electrons per cycle. In a perpendicular-to-plane magnetic field the plateaus become more pronounced indicating an improved current quantization. Current quantization is sustained up to magnetic fields where full spin polarization of the device can be expected.

PhysicsCondensed Matter - Mesoscale and Nanoscale PhysicsPhysics and Astronomy (miscellaneous)Spin polarizationCondensed matter physicsFOS: Physical sciencesHeterojunction02 engineering and technologyElectron021001 nanoscience & nanotechnologyCondensed Matter::Mesoscopic Systems and Quantum Hall Effect01 natural sciencesMagnetic fieldCharge pumpingQuantization (physics)Quantum dot0103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)010306 general physics0210 nano-technologyVoltage
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Constructive role of non-adiabaticity for quantized charge pumping

2010

We investigate a recently developed scheme for quantized charge pumping based on single-parameter modulation. The device was realized in an AlGaAl-GaAs gated nanowire. It has been shown theoretically that non-adiabaticity is fundamentally required to realize single-parameter pumping, while in previous multi-parameter pumping schemes it caused unwanted and less controllable currents. In this paper we demonstrate experimentally the constructive and destructive role of non-adiabaticity by analysing the pumping current over a broad frequency range.

PhysicsRange (particle radiation)Condensed Matter - Mesoscale and Nanoscale PhysicsNanowirePhysics::OpticsFOS: Physical sciences020206 networking & telecommunications02 engineering and technologyConstructiveTemperature measurementCharge pumpingModulationQuantum dotQuantum electrodynamicsMesoscale and Nanoscale Physics (cond-mat.mes-hall)0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingCurrent (fluid)
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