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

Physical review. B, Condensed matter

Many-particle effects on transient four-wave-mixing signals in semiconductors

Wilfried Schäfer, F. Jahnke, Stefan Schmitt-Rink

Published Jan 15, 1993• 58 citations
Publisher

Abstract

We discuss the temporal evolution of transient four-wave-mixing signals in semiconductors. For near-resonant excitation with intense ultrashort optical pulses, we show that even in a homogeneously broadened system, there is no pure free decay of the polarization. The bulk of the signal always appears delayed and its magnitude is determined by Coulomb interactions.

DOI
10.1103/physrevb.47.1217

Related papers

Effects of coherent polarization interactions on time-resolved degenerate four-wave mixing

Karl Leo, Martin Wegener, J. Shah +5 more

We report the first observation of coherent polarization interactions in dense media in time-resolved degenerate four-wave mixing in semiconductors. For near-resonant ultrashort-optical-pulse excitation, these interactions lead to a diffracted signal at negative delay times, with a slope half that for positive delay times. At higher intensities, two temporal maxima appear in the diffracted signal, in agreement with many-body theory.

Physical Review Letters•Sep 1, 1990•296 citations

Manybody-effects in nonlinear optics of semiconductors

Wilfried Schäfer

Many-body Coulomb interactions dominate nonlinear optical properties of semiconductor structures in many respects. Resulting effects show up most distinct in the temporal evolution of transient four-wave mixing signals. The simplest example in systems with homogeneously broadened absorption is the static exchange interaction, which prevents the occurrence of pure free polarization decay and gives rise to an additional interaction induced signal. For inhomogeneous broadening one obtains photon echo-like behaviour. The temporal duration of the signal, however, is not determined by the width of the inhomogeneous broadening, as is predicted by theory if interaction effects are neglected, but is much smaller due to exciton-exciton interaction. Additional to the static interaction effects electron-electron correlations give rise to laser induced renormalization and dephasing processes which depend sensitively on the polarizations of the driving fields. These effects are analyzed on the basis of quantum-kinetic equations, which allow to describe the temporal evolution of the nonlinear polarizations. Numerical results are presented for various excitation conditions and material systems.

Physica Scripta•Jan 1, 1994•1 citation

Observation of Many-Body Effects in the Femtosecond Temporal Profile of Quasi-2D Exciton Free-Induction Decay

Shimon Weiss, Mary‐Ann Mycek, J.-Y. Bigot +2 more

In time-resolved four-wave mixing (FWM) experiments, two ultrashort pulses delayed by Δt and with wavevectors k1 and k2 interfere in a sample to produce a diffracted signal (DS) in the direction ks = 2 k2 − k1. In the case of a homogeneously broadened system, the DS is emitted immediately after the second pulse corresponding to the "free- induction decay" of the nonlinear polarization. Because of the short dephasing times T2 in solids, the DS is usually not time-resolved, but is measured as a function of Δt using a slow detector. Valuable information contained in the temporal profile of the DS is thus lost Here, we report the first measurement of the temporal evolution of the DS on a fs time scale for the case of selective excitation of semiconductors.

International Conference on Ultrafast Phenomena•Jan 1, 1992•1 citation

Femtosecond coherent fields induced by many-particle correlations in transient four-wave mixing

W. Schäfer, D. S. Kim, Jagdeep Shah +5 more

We present a unified microscopic approach to four-wave mixing (FWM) in semiconductors on an ultrashort time scale. The theory is valid for resonant excitation in the vicinity of the excitonic resonance and at low densities. The most important many-particle effects, i.e., static and dynamical exciton-exciton interaction as well as biexcitonic effects are incorporated. The internal fields resulting from these interaction processes give rise to pronounced many-particle effects in FWM signals. Our results explain the dependence of FWM signals on the polarization geometry, especially if biexcitons contribute. Time-resolved (TR) FWM experiments show that the diffraction of the interaction induced fields dominate the FWM signals completely. This dominance of the interaction induced field at low temperatures is true regardless of density, detuning, or polarization geometry. While spectrally resolved FWM (-FWM) shows biexcitonic or bound excitonic contributions under various experimental conditions, TR-FWM is always completely delayed, peaking roughly at the dephasing time after both beams passed through. \textcopyright{} 1996 The American Physical Society.

Physical review. B, Condensed matter•Jun 15, 1996•105 citations

Unusually slow temporal evolution of femtosecond four-wave-mixing signals in intrinsic GaAs quantum wells: Direct evidence for the dominance of interaction effects

Dai‐Sik Kim, Jagdeep Shah, Theo C. Damen +4 more

Four-wave-mixing signals from excitons in high-quality GaAs quantum wells show an unusually slow temporal evolution, in stark contrast to the behavior expected for a noninteracting two-level system. We show that Coulomb interaction effects, generally neglected in the analyses of four-wave-mixing experiments, dominate the signals by 2 orders of magnitude. Numerical calculations based on extended optical Bloch equations for semiconductors provide good qualitative agreement with the data.

Physical Review Letters•Nov 2, 1992•188 citations

Pulse Propagation and Many-body Effects in Semiconductor Four Wave Mixing

A. Schulze, A. Knorr, S. W. Koch

The simultaneous influence of pulse propagation and Coulomb many-body interaction in Four Wave Mixing experiments is theoretically studied using the Semiconductor-Maxwell-Bloch equations. In this framework, the propagation of the optical fields and the microscopic interaction of the light with the semiconductor are treated consistently. The Maxwell equation is used as a reduced wave equation and the many-body Coulomb interaction are treated at the level of a screened Hartree-Fock approximation including phenomenological decay terms. We have analyzed the interplay of the propagation and Coulomb effects by calculating the Four Wave Mixing signal (FWMS) for different sample lengths and various excitation conditions, i.e, for pulses with different intensities at the exciton and in the continuum.

Quantum Optoelectronics•Jan 1, 1995•0 citations
We discuss the temporal evolution of transient four-wave-mixing signals in semiconductors. For near-resonant excitation with intense ultrashort optical pulses, we show that even in a homogeneously broadened system, there is no pure free decay of the polarization. The bulk of the signal always appears delayed and its magnitude is determined by Coulomb interactions.
Many-body Coulomb interactions dominate nonlinear optical properties of semiconductor structures in many respects. Resulting effects show up most distinct in the temporal evolution of transient four-wave mixing signals. The simplest example in systems with homogeneously broadened absorption is the static exchange interaction, which prevents the occurrence of pure free polarization decay and gives rise to an additional interaction induced signal. For inhomogeneous broadening one obtains photon echo-like behaviour. The temporal duration of the signal, however, is not determined by the width of the inhomogeneous broadening, as is predicted by theory if interaction effects are neglected, but is much smaller due to exciton-exciton interaction. Additional to the static interaction effects electron-electron correlations give rise to laser induced renormalization and dephasing processes which depend sensitively on the polarizations of the driving fields. These effects are analyzed on the basis of quantum-kinetic equations, which allow to describe the temporal evolution of the nonlinear polarizations. Numerical results are presented for various excitation conditions and material systems.
In time-resolved four-wave mixing (FWM) experiments, two ultrashort pulses delayed by Δt and with wavevectors k1 and k2 interfere in a sample to produce a diffracted signal (DS) in the direction ks = 2 k2 − k1. In the case of a homogeneously broadened system, the DS is emitted immediately after the second pulse corresponding to the "free- induction decay" of the nonlinear polarization. Because of the short dephasing times T2 in solids, the DS is usually not time-resolved, but is measured as a function of Δt using a slow detector. Valuable information contained in the temporal profile of the DS is thus lost Here, we report the first measurement of the temporal evolution of the DS on a fs time scale for the case of selective excitation of semiconductors.
We present a unified microscopic approach to four-wave mixing (FWM) in semiconductors on an ultrashort time scale. The theory is valid for resonant excitation in the vicinity of the excitonic resonance and at low densities. The most important many-particle effects, i.e., static and dynamical exciton-exciton interaction as well as biexcitonic effects are incorporated. The internal fields resulting from these interaction processes give rise to pronounced many-particle effects in FWM signals. Our results explain the dependence of FWM signals on the polarization geometry, especially if biexcitons contribute. Time-resolved (TR) FWM experiments show that the diffraction of the interaction induced fields dominate the FWM signals completely. This dominance of the interaction induced field at low temperatures is true regardless of density, detuning, or polarization geometry. While spectrally resolved FWM (-FWM) shows biexcitonic or bound excitonic contributions under various experimental conditions, TR-FWM is always completely delayed, peaking roughly at the dephasing time after both beams passed through. \textcopyright{} 1996 The American Physical Society.
The simultaneous influence of pulse propagation and Coulomb many-body interaction in Four Wave Mixing experiments is theoretically studied using the Semiconductor-Maxwell-Bloch equations. In this framework, the propagation of the optical fields and the microscopic interaction of the light with the semiconductor are treated consistently. The Maxwell equation is used as a reduced wave equation and the many-body Coulomb interaction are treated at the level of a screened Hartree-Fock approximation including phenomenological decay terms. We have analyzed the interplay of the propagation and Coulomb effects by calculating the Four Wave Mixing signal (FWMS) for different sample lengths and various excitation conditions, i.e, for pulses with different intensities at the exciton and in the continuum.