© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Quantum Electronics and Laser Science Conference

Spectrally resolved stationary resonance fluorescence from excitons in GaAs quantum wells: Rayleigh scattering and non-classical effects

D. Schwest, Ch. Nacke, H. Stolz, Soheyla Eshlagi, D. Reuter, Andreas Dirk Wieck

Published Jun 25, 2003• 0 citations

Abstract

Summary form only given. After the first observation of resonance scattering from excitons in quantum wells about 1980, this topic has received much interest and has given rise to a hot debate on the origin of this scattering process. Recently, the determination of the temporal behaviour and the coherence properties of this scattering has initiated revival of interferometric techniques in semiconductor optics. Finally, the observation of speckles in the angular distribution proved that this scattering indeed originates from exciton states localized by disorder. However, complementary information on the nature of the excitons and the interplay between scattering and luminescence can be obtained from high resolution cw spectroscopy, having the advantage that only a small fraction of the states within the homogeneous linewidth is excited. However yhe polarization behaviour is quite different for the coherent Rayleigh component and the luminescence, depending on the orientation, splitting and relaxation of the localized states. The experimental results for a 20 nm wide GaAs quantum well clearly confirm this prediction.

DOI: 10.1109/qels.2002.1031166

Related papers

Homogeneous linewidth of quantum well excitonsfrom resonance fluorescence spectra

Daniel Schwedt, Ch. Nacke, H. Stolz +3 more

Abstract Editor's Choice of this issue is the article by D. Schwedt et al. [1] on high resolution measurements of resonance fluorescence spectra from GaAs quantum wells. In the cover picture, the authors point out the connection between the experimental data and the model of disordered excitons. The lower left part shows a series of polarized photoluminescence spectra, fitted with very good agreement by a model of statistically distributed three‐level‐systems. The upper right part images the excitation mechanism. Only those excitons of an inhomogeneous distribution (indicated by the blue line) contribute to the resonance fluorescence (red line) which overlap spectrally with the monochromatic laser. It could be verified experimentally that the resonance fluorescence exhibits two parts: delta‐like Rayleigh scattering and Lorentzian luminescence. Daniel Schwedt is working in the DFG research group 'Quantum Optics in Semiconductor Nanostructures' and concentrates on quantum optical experiments on III–V semiconductor quantum well structures.

physica status solidi (b)•Oct 22, 2003•1 citation

Coherence and relaxation of excitons in transform-limited time-resolved resonant light-scattering

H. Stolz

Utilizing transform-limited time-resolved light scattering with simultaneously optimum temporal and spectral resolution, it is possible to investigate on a picosecond time scale energy and phase relaxation processes of excitons in semiconductors. Thereby quantum-beating as a measure of exciton coherence allows us to discriminate Raman scattering from hot luminescence as exemplified for indirect free excitons in AgBr. In order to distinguish resonant Rayleigh scattering occurring in disordered systems from ordinary fluorescence, the experimental setup has to be fully included in the theoretical description of the light scattering process. Experiments at the (n equals 1, e-hh) exciton in GaAs/AlGaAs quantum well structures confirm the predicted finite decay of this process and allow us to measure the exciton relaxation dynamics.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 6, 1994•1 citation

Ultrafast secondary radiation of excitons in quantum wells: The transition from the coherent to the incoherent regime

Stefan Haacke, Gary R. Hayes, Robert Anthony Taylor +2 more

Coherent Rayleigh scattering and incoherent luminescence are studied by femtosecond upconversion under resonant excitation as a function of exciton density in GaAs quantum wells. Comparing samples with different well widths allows to establish the relation between inhomogeneous broadening and the shape of resonant Rayleigh scattering. We find an excellent agreement between experiment and a classical model. In samples with moderate inhomogeneous broadening we provide evidence for the transition from coherent to incoherent emission. The comparison with excitonic dephasing times T2 obtained from four-wave-mixing experiments demonstrates that the incoherent exciton population rises within T2/2, at any exciton density when changed by more than an orders of magnitude. The experimental results confirm very clearly the concept predicting that the coherent polarization made up by localized excitons decays into an incoherent exciton population under conservation of the number of excited quanta.

Radiative Processes and Dephasing in Semiconductors•Jan 1, 1998•0 citations

Interferometric analysis of resonant Rayleigh scattering from two-dimensional excitons

Stefan Haacke, Sacha Schaer, B. Deveaud +1 more

We have performed spectral interferometry with Rayleigh scattered light coming from a single speckle and emitted after resonant creation of excitons in GaAs quantum wells. The experiment confirms the coherence of the secondary emission at early times, regardless of sample parameters, but underlines the stochastic nature of a single speckle. The scattered electric field is calculated, correctly accounting for the center-of-mass quantization in the disordered potential. We find that the amplitudes of the electric fields emitted by different excitons are uncorrelated, so that the well-known Poisson distribution for speckle intensities applies.

Physical review. B, Condensed matter•Feb 15, 2000•24 citations

Experimental Investigation of Quantum Effects in Time-Resolved Resonant Rayleigh Scattering from Quantum Well Excitons

D. Birkedal, Jagdeep Shah, Andrei V. Shchegrov +1 more

Resonant Rayleigh scattering from quantum well excitons is investigated using ultrafast spectral interferometry. We isolate the coherent Rayleigh scattering from incoherent luminescence in a single speckle. Averaging the resonant Rayleigh intensity over several speckles allows us to identify features in support of quantum corrections to the classical description of the underlying scattering process.

physica status solidi (a)•Mar 1, 2000•3 citations

Coherent emission from excitons in quantum well structures

Ch. Nacke, Frank Kieseling, H. Stolz

Summary form only given. The question of the coherence properties of the radiation from two-dimensional electron-hole-pair states in systems of reduced dimensionality has recently gained new interest both in theory and experiment. In these experiments the light emission from a short-pulse excited semiconductor QW in a direction different from the excitation or reflection directions (secondary emission, SE) was studied either by spectral interferometry or speckle analysis. As origin of the SE either disorder or Coulomb interaction is under discussion. We report in our contribution a careful study of both the specular and non-specular resonant-emission from GaAs quantum well exciton states applying interferometric controlled spectral interferometry with an accuracy of about 50 attosetonds.

Quantum Electronics and Laser Science Conference•May 7, 2000•0 citations

Summary form only given. After the first observation of resonance scattering from excitons in quantum wells about 1980, this topic has received much interest and has given rise to a hot debate on the origin of this scattering process. Recently, the determination of the temporal behaviour and the coherence properties of this scattering has initiated revival of interferometric techniques in semiconductor optics. Finally, the observation of speckles in the angular distribution proved that this scattering indeed originates from exciton states localized by disorder. However, complementary information on the nature of the excitons and the interplay between scattering and luminescence can be obtained from high resolution cw spectroscopy, having the advantage that only a small fraction of the states within the homogeneous linewidth is excited. However yhe polarization behaviour is quite different for the coherent Rayleigh component and the luminescence, depending on the orientation, splitting and relaxation of the localized states. The experimental results for a 20 nm wide GaAs quantum well clearly confirm this prediction.

Abstract Editor's Choice of this issue is the article by D. Schwedt et al. [1] on high resolution measurements of resonance fluorescence spectra from GaAs quantum wells. In the cover picture, the authors point out the connection between the experimental data and the model of disordered excitons. The lower left part shows a series of polarized photoluminescence spectra, fitted with very good agreement by a model of statistically distributed three‐level‐systems. The upper right part images the excitation mechanism. Only those excitons of an inhomogeneous distribution (indicated by the blue line) contribute to the resonance fluorescence (red line) which overlap spectrally with the monochromatic laser. It could be verified experimentally that the resonance fluorescence exhibits two parts: delta‐like Rayleigh scattering and Lorentzian luminescence. Daniel Schwedt is working in the DFG research group 'Quantum Optics in Semiconductor Nanostructures' and concentrates on quantum optical experiments on III–V semiconductor quantum well structures.

Utilizing transform-limited time-resolved light scattering with simultaneously optimum temporal and spectral resolution, it is possible to investigate on a picosecond time scale energy and phase relaxation processes of excitons in semiconductors. Thereby quantum-beating as a measure of exciton coherence allows us to discriminate Raman scattering from hot luminescence as exemplified for indirect free excitons in AgBr. In order to distinguish resonant Rayleigh scattering occurring in disordered systems from ordinary fluorescence, the experimental setup has to be fully included in the theoretical description of the light scattering process. Experiments at the (n equals 1, e-hh) exciton in GaAs/AlGaAs quantum well structures confirm the predicted finite decay of this process and allow us to measure the exciton relaxation dynamics.

Coherent Rayleigh scattering and incoherent luminescence are studied by femtosecond upconversion under resonant excitation as a function of exciton density in GaAs quantum wells. Comparing samples with different well widths allows to establish the relation between inhomogeneous broadening and the shape of resonant Rayleigh scattering. We find an excellent agreement between experiment and a classical model. In samples with moderate inhomogeneous broadening we provide evidence for the transition from coherent to incoherent emission. The comparison with excitonic dephasing times T2 obtained from four-wave-mixing experiments demonstrates that the incoherent exciton population rises within T2/2, at any exciton density when changed by more than an orders of magnitude. The experimental results confirm very clearly the concept predicting that the coherent polarization made up by localized excitons decays into an incoherent exciton population under conservation of the number of excited quanta.

We have performed spectral interferometry with Rayleigh scattered light coming from a single speckle and emitted after resonant creation of excitons in GaAs quantum wells. The experiment confirms the coherence of the secondary emission at early times, regardless of sample parameters, but underlines the stochastic nature of a single speckle. The scattered electric field is calculated, correctly accounting for the center-of-mass quantization in the disordered potential. We find that the amplitudes of the electric fields emitted by different excitons are uncorrelated, so that the well-known Poisson distribution for speckle intensities applies.

Summary form only given. The question of the coherence properties of the radiation from two-dimensional electron-hole-pair states in systems of reduced dimensionality has recently gained new interest both in theory and experiment. In these experiments the light emission from a short-pulse excited semiconductor QW in a direction different from the excitation or reflection directions (secondary emission, SE) was studied either by spectral interferometry or speckle analysis. As origin of the SE either disorder or Coulomb interaction is under discussion. We report in our contribution a careful study of both the specular and non-specular resonant-emission from GaAs quantum well exciton states applying interferometric controlled spectral interferometry with an accuracy of about 50 attosetonds.