Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Quantum Electronics and Laser Science Conference

Transfer of coherence properties between exciton and continuum transitions in semiconductor quantum wells

S. Arlt, J. Kunde, François Morier-Genoud, Ursula Keller, U. Siegner

Published Jan 1, 2000• 0 citations
OpenAlex

Abstract

Summary form only given. Coherent dynamics in semiconductors can be strongly affected by interaction between energetically degenerate interband transitions. In this paper, we demonstrate for the first time to our knowledge that this strong interaction can be used to transfer the coherence properties of discrete excitons to continuum transitions and vice versa. This transfer can generate coherent radiation from the continuum, which is absent otherwise. Our results can be understood in a model that describes the strongly interacting exciton and continuum transitions as a multitude of excited states coupled to a common ground state. The transfer of coherence properties should be observable in any multilevel system with a common ground state.

Related papers

Transfer of coherent dynamics between discrete excitons and exciton Fano continua in quantum wells

S. Arlt, J. Kunde, François Morier-Genoud +2 more

Four-wave-mixing in semiconductor quantum wells with spectrally shaped broadband laser pulses demonstrates that the coherent dynamics of discrete excitons can be detected in the coherent emission from exciton Fano continua and vice versa. In particular, quantum beating between discrete heavy and light hole excitons is observed in the coherent emission from the continuum. The results can be understood in a common ground-state picture of strongly coupled transitions. This model shows that the transfer of the amplitude of the nonlinear coherent polarization is at the origin of the experimental results.

Physical review. B, Condensed matter•Jul 15, 2000•3 citations

Coherent exciton-continuum coupling in semiconductors

Steven T. Cundiff, M. Koch, Wayne H. Knox +2 more

Summary form only given. Despite recent effort, there are aspects of the transient four-wave-mixing (TFWM) response of semiconductors that remain puzzling. By performing partially nondegenerate TFWM (PND-TFWM) we show that for broadband excitation, the signal emitted at the 1 s exciton is dominated by contributions that correspond to excitation of higher states by the first pulse. The interference of these contributions results in the rapid decay of the excitonic signal. Our results demonstrate that, because TFWM is inherently a many-particle phenomenon, the many-body interactions always couple the excitonic transitions.

Quantum Electronics and Laser Science Conference•Jun 7, 1996•0 citations

Coherent coupling between continuum states and excitons in semiconductors due to excitation-induced-dephasing

Justin M. Shacklette, Steven T. Cundiff, W. Stolz

Summary form only given. Our experimental data shows that excitation induced dephasing (EID) is the coupling mechanism between continuum states and the exciton. The fact that both the transient four wave mixing (TFWM) and PND-TFWM experiments have the same dependence on pre-pulse power demonstrates that the coherent emission of the exciton is dominated by EID mediated coupling to the continuum for broadband excitation.

Quantum Electronics and Laser Science Conference•Jan 20, 2003•0 citations

Ultrafast coherent dynamics of excitons of higher-order subbands in semiconductor quantum wells

S. Arlt, U. Siegner, François Morier-Genoud +1 more

The coherent emission from excitons corresponding to different subband transitions in a 500 Åbroad GaAs/AlGaAs quantum well is studied by spectrally resolved transient four-wave mixing (FWM). For the simultaneous excitation of several subband transitions, the dephasing times of the lowest exciton and higher- order exciton transitions are determined from the width of the resonances in the FWM spectrum. The decay of the spectrally integrated FWM signal as a function of the time delay between the excitation laser pulses does not reflect the dephasing times but is determined by the laser pulse width for multi-subband excitation. This is indicative of quantum interference between exciton and continuum transitions. Many-body Coulomb effects have to be included in a theoretical treatment of these experimental observations.

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

Theory of excitonic optical properties of semiconductor quantum wells and Bragg structures

Zhenshan S. Yang

This dissertation addresses both fundamental aspects of the coherent exciton kinetics in single semiconductor quantum wells and more application-oriented aspects of the collective excitonic optical properties in quantum well Bragg structures. We use a bosonic theory to investigate the ultrafast coherent exciton dynamics after an optical excitation in a single semiconductor quantum well. It is shown that, on intermediate time scales, nonlinear mean-field interactions between excitons lead to a coherent, wave-like evolution in the momentum distribution of optically inactive excitons, which can survive for some time before dephasing sets in. Driven by two-exciton correlations, this coherent quantum kinetic effect bridges the well-known kinetics associated with optical excitation on the one hand and incoherent relaxation on the other. We also study more general dynamical properties of bosonic mean field systems with N-species of excitons (in a single semiconductor quantum well). We find that the momentum-conserving exciton mean field equations, including the coupling to external fields and fermionic corrections, have the dynamical structure su(N,N). We show that one can define a non-real generalized "Bloch vector" and a non-hermitian "density matrix" description, which allow us to explicitly obtain all the constants of motion associated with the su(N,N) symmetry. The many-body effects and correlations of excitons in a single quantum well are mainly induced by the Coulomb interactions. In the case of a semiconductor quantum well Bragg structure, the light induced coupling between different quantum wells also dramatically affects the excitons' behavior, especially through the collective excitations of excitons in the whole structure. We investigate the linear excitonic optical properties of the quantum well Bragg structure induced by the collective excitations using the transfer matrix approach. We show that the so called "intermediate band" (IB) created by the exciton resonance, which does not exist in conventional photonic crystals, can be used for the stopping, storing and releasing of light, which is important in information processing devices. We also discuss the compensation of the dispersive distortion in the light delay process through reversing the IB band structure. Other conceptual and practical issues such as the decay rate of the IB modes and the generalized anti-reflection coating are also investigated.

•Jan 1, 2005•0 citations

Coherent excitonic gain under resonant excitation in semiconductor quantum wells

Mark C. Phillips, Hailin Wang

Summary form only given. Strong resonant excitation of atoms can lead to Mollow spectra in saturation spectroscopy, with gain near the Rabi sidebands or with a coherent dip at the atomic resonance. In this paper we report experimental studies on the manifestation of Mollow spectra and especially gain in an excitonic system. We observe a spectrally sharp coherent excitonic gain in a semiconductor quantum well under strong resonant excitation. Theoretical analysis based on modified optical Bloch equations (MOBE) indicates that this coherent gain differs qualitatively from its counterpart in atomic systems and is a direct result of exciton-exciton interactions. Understanding the manifestation of Mollow spectra and gain in an excitonic system provides important insight into coherent optical interactions in semiconductors and is of importance in understanding recently observed parametric gain associated with exciton-polaritons in semiconductor microcavities.

Quantum Electronics and Laser Science Conference•Nov 13, 2002•0 citations
Summary form only given. Coherent dynamics in semiconductors can be strongly affected by interaction between energetically degenerate interband transitions. In this paper, we demonstrate for the first time to our knowledge that this strong interaction can be used to transfer the coherence properties of discrete excitons to continuum transitions and vice versa. This transfer can generate coherent radiation from the continuum, which is absent otherwise. Our results can be understood in a model that describes the strongly interacting exciton and continuum transitions as a multitude of excited states coupled to a common ground state. The transfer of coherence properties should be observable in any multilevel system with a common ground state.
Four-wave-mixing in semiconductor quantum wells with spectrally shaped broadband laser pulses demonstrates that the coherent dynamics of discrete excitons can be detected in the coherent emission from exciton Fano continua and vice versa. In particular, quantum beating between discrete heavy and light hole excitons is observed in the coherent emission from the continuum. The results can be understood in a common ground-state picture of strongly coupled transitions. This model shows that the transfer of the amplitude of the nonlinear coherent polarization is at the origin of the experimental results.
Summary form only given. Despite recent effort, there are aspects of the transient four-wave-mixing (TFWM) response of semiconductors that remain puzzling. By performing partially nondegenerate TFWM (PND-TFWM) we show that for broadband excitation, the signal emitted at the 1 s exciton is dominated by contributions that correspond to excitation of higher states by the first pulse. The interference of these contributions results in the rapid decay of the excitonic signal. Our results demonstrate that, because TFWM is inherently a many-particle phenomenon, the many-body interactions always couple the excitonic transitions.
The coherent emission from excitons corresponding to different subband transitions in a 500 Åbroad GaAs/AlGaAs quantum well is studied by spectrally resolved transient four-wave mixing (FWM). For the simultaneous excitation of several subband transitions, the dephasing times of the lowest exciton and higher- order exciton transitions are determined from the width of the resonances in the FWM spectrum. The decay of the spectrally integrated FWM signal as a function of the time delay between the excitation laser pulses does not reflect the dephasing times but is determined by the laser pulse width for multi-subband excitation. This is indicative of quantum interference between exciton and continuum transitions. Many-body Coulomb effects have to be included in a theoretical treatment of these experimental observations.
This dissertation addresses both fundamental aspects of the coherent exciton kinetics in single semiconductor quantum wells and more application-oriented aspects of the collective excitonic optical properties in quantum well Bragg structures. We use a bosonic theory to investigate the ultrafast coherent exciton dynamics after an optical excitation in a single semiconductor quantum well. It is shown that, on intermediate time scales, nonlinear mean-field interactions between excitons lead to a coherent, wave-like evolution in the momentum distribution of optically inactive excitons, which can survive for some time before dephasing sets in. Driven by two-exciton correlations, this coherent quantum kinetic effect bridges the well-known kinetics associated with optical excitation on the one hand and incoherent relaxation on the other. We also study more general dynamical properties of bosonic mean field systems with N-species of excitons (in a single semiconductor quantum well). We find that the momentum-conserving exciton mean field equations, including the coupling to external fields and fermionic corrections, have the dynamical structure su(N,N). We show that one can define a non-real generalized "Bloch vector" and a non-hermitian "density matrix" description, which allow us to explicitly obtain all the constants of motion associated with the su(N,N) symmetry. The many-body effects and correlations of excitons in a single quantum well are mainly induced by the Coulomb interactions. In the case of a semiconductor quantum well Bragg structure, the light induced coupling between different quantum wells also dramatically affects the excitons' behavior, especially through the collective excitations of excitons in the whole structure. We investigate the linear excitonic optical properties of the quantum well Bragg structure induced by the collective excitations using the transfer matrix approach. We show that the so called "intermediate band" (IB) created by the exciton resonance, which does not exist in conventional photonic crystals, can be used for the stopping, storing and releasing of light, which is important in information processing devices. We also discuss the compensation of the dispersive distortion in the light delay process through reversing the IB band structure. Other conceptual and practical issues such as the decay rate of the IB modes and the generalized anti-reflection coating are also investigated.
Summary form only given. Strong resonant excitation of atoms can lead to Mollow spectra in saturation spectroscopy, with gain near the Rabi sidebands or with a coherent dip at the atomic resonance. In this paper we report experimental studies on the manifestation of Mollow spectra and especially gain in an excitonic system. We observe a spectrally sharp coherent excitonic gain in a semiconductor quantum well under strong resonant excitation. Theoretical analysis based on modified optical Bloch equations (MOBE) indicates that this coherent gain differs qualitatively from its counterpart in atomic systems and is a direct result of exciton-exciton interactions. Understanding the manifestation of Mollow spectra and gain in an excitonic system provides important insight into coherent optical interactions in semiconductors and is of importance in understanding recently observed parametric gain associated with exciton-polaritons in semiconductor microcavities.