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Article
Cathodoluminescence study of GaN-based film structures
GaN films grown on sapphire substrate with an emphasis on epitaxial lateral overgrown (ELOG) layers with an array of rhombic shaped mask area as well as InGaN/GaN MQW laser diode layer structures were investig...
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Chapter and Conference Paper
Fine Structure of Excitons in Quantum Wires
The fine structure of the localized exciton ground state is studied in GaAs/AlAs quantum wires. Polarization of photoluminescence under the polarized excitation and spin-flip Raman scattering versus external m...
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Chapter and Conference Paper
Superradiant exciton/light coupling in semiconductor heterostructures—Part II: Experiments
Time-integrated and time-resolved degenerate four-wave mixing as well as reflection measurements with subpicosecond optical pulses are applied to study the nonlinearity and dynamics of coupled exciton/photon m...
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Article
Raman spectroscopy of resonance exciton tunneling in GaAs/AlAs superlattices in electric fields
Optical-resonance-Raman scattering by acoustic phonons is used to study the effect of an electric field on the state of excitons in GaAs/AlAs superlattices. When the energy of the exciting photon coincides wit...
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Chapter and Conference Paper
Ultrafast pump-probe signals at the band edge of bulk GaAs: Excitonic versus free carrier contributions
Polarization selection rules allow an experimental separation of free carrier from excitonic heavy-light hole quantum beats in fs-pump-probe signals at the absorption edge of GaAs.
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Article
Investigation of the interface roughness of GaAs single quantum wells by X-ray diffractometry, reflectivity and diffuse scattering
We investigate thin GaAs single quantum wells with barriers consisting of AlAs/GaAs short-period superlattices by X-ray diffraction, reflection and diffuse scattering and by atomic force microscopy. The sample...
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Article
Capacitance spectroscopy investigation of the spin polarization of two-dimensional electronic systems
It is shown that capacitance spectroscopy can be used to investigate the spin polarization of two-dimensional electronic systems (2DESs). We employed this method to investigate the spin polarization of 2DESs i...
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Chapter and Conference Paper
Superradiant Terahertz Emission from Bloch Oscillations
The superradiance of terahertz radiation from impulsively excited phase-synchronous Bloch oscillations in a AlGaAs/GaAs superlattice is demonstrated.
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Chapter and Conference Paper
Spin Quantum Beats in Bulk and Low Dimensional Semiconductors
The electron Lande g factor is one of the basic parameters in semiconductors which describes the magnitude of the Zeeman splitting of electronic states in magnetic fields. Since various theoretical models pred...
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Chapter
Exciton/Exciton Coupling in Multiple Quantum Well Bragg Structures
In the last years, comprehensive theoretical and experimental work has led to rapid progress in the understanding of exciton-exciton interactions, contributing to the nonlinear optical response, such as local ...
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Chapter and Conference Paper
Heavy-Light Hole Quantum Beats in the Band-to-Band Continuum of Bulk GaAs Studied in 20 fs Pump-Probe Experiments
Interband excitation of GaAs with 20 fs pulses creates a coherent polarization between the heavy and light hole continuum, giving rise to quantum beats on a 150 fs time scale.
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Chapter
Ultrafast Coherent Carrier Control in Quantum Structures
The advent of stable sources of ultrafast laser pulses has stimulated the investigation of coherent dynamics in solid-state systems.1 Phase becomes an important factor in interactions with matter when the optical...
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Chapter
Dephasing of Excitons in Multiple Quantum Well Bragg Structures
The recent progress in the development of ultrashort laser pulses enables observations of the coherent dynamics of excitons in quantum wells (QW) with less than 100 fs time resolution by transient degenerate-f...
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Chapter and Conference Paper
Femtosecond Coherent Spin Control in Quantum Wells
We demonstrate the coherent control of spin in quantum wells with phase-locked pairs of perpendicularly polarised 100 fs pulses. These pulses induce strong interference in the electron spin polarisation, which...
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Article
Thermally activated dissipative conductivity in the fractional quantum Hall effect regime
Experimental investigations of thermally activated dissipative conductivity σxx in the fractional quantum Hall effect at filling factors v=1/3 and near zero were performed with GaAs/AlGaAs heterojunction based fi...
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Chapter and Conference Paper
Enhanced Radiative Decay and Optical Dephasing of Excitons in GaAs Quantum Well Bragg Structures
Femtosecond spectroscopy on excitons in quantum well Bragg structures shows efficient radiative interwell coupling implying enhanced radiative recombination.
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Article
Polarization anisotropies in (113)-oriented GaAs/AlAs Superlattices
We report on a theoretical calculation of the optical anisotropies in (113)-grown corrugated GaAs/AlAs superlattices using a 6-bankk·p valence band Hamiltonian. By comparison of the calculation with the experimen...
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Article
In-situ monitoring of interface formation using the phase shift of reflection high-energy electron diffraction intensity oscillations
A novel phase shift of Reflection High-Energy Electron Diffraction (RHEED) intensity oscillations during heterointerface formation allows direct monitoring of segragation at GaAs/Al x ...
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Chapter
Laterally Ordered Incorporation of Impurity Atoms on Vicinal GaAs(001) Surfaces
The surface processes during Si deposition on singular and vicinal GaAs(001) surfaces have been studied in real time by reflection high-energy electron diffraction (RHEED) and reflectance anisotropy spectrosco...
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Chapter
Transport Experiments on a Quantum Dot
Electron transport through a mesoscopic electronic island is dominated by the electron-electron interaction leading to the so-called Coulomb blockade (CB) effect and single-electron tunneling (SET). In figure ...
