31 Result(s)
within
W. Wegscheider
Physics
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Article
Spin-selective strong light–matter coupling in a 2D hole gas-microcavity system
The interplay between time-reversal symmetry breaking and strong light–matter coupling in two-dimensional (2D) gases brings intriguing aspects to polariton physics. This combination can lead to a polarization/...
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Article
Strong photon coupling to the quadrupole moment of an electron in a solid-state qubit
The fundamental concept of light–matter interaction is routinely realized by coupling the quantized electric field in a cavity to the dipole moment of a real or an artificial atom. A recent proposal1,2, motivated...
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Article
Open AccessLoading a quantum-dot based “Qubyte” register
Electrostatically defined quantum dot arrays offer a compelling platform for quantum computation and simulation. However, tuning up such arrays with existing techniques becomes impractical when going beyond a ...
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Article
Electron Spin Resonance in an AlAs Quantum Well near Filling Factor 1
The phenomenon of spin resonance of two-dimensional electrons confined in a 16 nm AlAs quantum well is studied in the quantum Hall effect regime near filling factor 1. At a temperature of T = 0.5K, spin resonance...
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Article
Electron paramagnetic resonance study of the nuclear spin dynamics in an AlAs quantum well
The nuclear spin dynamics in an asymmetrically doped 16-nm AlAs quantum well grown along the [001] direction has been studied experimentally using the time decay of the Overhauser shift of paramagnetic resonan...
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Article
Direct map** of the formation of a persistent spin helix
The spin–orbit interaction (SOI) in zincblende semiconductor quantum wells can be set to a symmetry point, in which spin decay is strongly suppressed for a helical spin mode. Signatures of such a persistent sp...
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Article
Quantum interference and phonon-mediated back-action in lateral quantum-dot circuits
You influence a system by measuring it. This back-action is an important consideration when studying tiny structures in which quantum effects play a crucial role. Researchers now show that quantum interference...
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Article
Local investigation of the energy gap within the incompressible strip in the quantum Hall regime
We experimentally study the energy gap within the incompressible strip at local filling factor ν c = 1 at the quantum Hall edge for samples of very different mobilities. The obt...
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Article
Confluence of resonant laser excitation and bidirectional quantum-dot nuclear-spin polarization
Resonant laser scattering along with photon correlation measurements established the atom-like character of quantum dots. Here, we show that for a wide range of experimental parameters it is impossible to isol...
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Chapter and Conference Paper
Investigations on a dilute magnetic semicondutor (Ga1−xMnxAs) by conventional TEM and EELS
The Dilute Magnetic Semiconductor (DMS) Ga1−xMnxAs offers good prospects for the integration of ferromagnetic and semiconducting properties for use in future “spintronic” applications [1].
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Article
Cross-sectional imaging of spin injection into a semiconductor
Recent discoveries of phenomena that relate electronic transport in solids to the spin angular momentum of the electrons are the fundamentals of spin electronics (spintronics). The first proposed conceptual sp...
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Article
Hole-density dependence of the cyclotron mass of 2D holes in a GaAs(001) quantum well
The dependence of the heavy-hole cyclotron mass in GaAs(001) quantum wells on the 2D-hole density has been measured by the optical detection method for resonance microwave by-absorption. A significant increase...
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Article
Spin photocurrents and the circular photon drag effect in (110)-grown quantum well structures
The study of spin photocurrents in (110)-grown quantum well structures is reported. The investigated effects comprise the circular photogalvanic effect and so far not observed circular photon drag effect. The ...
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Article
Experimental investigation of the edge states structure at fractional filling factors
We experimentally study the electron transport between edge states in the fractional quantum Hall effect regime. We find an anomalous increase of the transport across the 2/3 incompressible fractional stripe i...
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Chapter
The Structure and Dispersion of a Sharp Quantum Hall Edge Probed by Momentum-Resolved Tunneling
We present measurements of momentum-resolved magneto-tunneling from a perpendicular two-dimensional (2D) contact into integer quantum Hall (QH) edges at a sharp edge potential created by cleaved edge overgrow...
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Article
Cyclotron Resonance of Composite Fermions
The introduction of suitable fictitious entities occasionally permits to cast otherwise difficult strongly interacting many-body systems in a single particle form. We can then take the customary physical appro...
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Article
Spin-Galvanic Effect in Quantum Wells
It is shown that a homogeneous nonequlibrium spin polarization in semiconductor hetero- structures results in an electric current. The microscopic origin of the effect is an inherent asymmetry of spin-flip sca...
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Chapter and Conference Paper
Cyclotron Resonance of Composite Fermions
The introduction of suitable fictitious entities occasionally permits to cast otherwise difficult strongly interacting many-body systems in a single particle form. We can then take the customary physical appro...
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Article
Cyclotron spin-wave in the 2D electron system
The cyclotron spin-wave mode of a two-dimensional electron system have been investigated by inelastic light scattering. It is observed at small electron filling factors, (v∼0.1, when the electron system is spin-d...
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Chapter
Electronic Properties of AFM-Defined Semiconductor Nanostructures: Quantum Wires and Single Electron Transistors
The electron gas in AlGaAs heterostructures can be depleted below regions which are patterned with an atomic force microscope. This leads to laterally insulating regions across which in-plane gate voltages can...
