Observation of inter-Landau-level quantum coherence in semiconductor quantum wells

Abstract

Using three-pulse four-wave-mixing femtosecond spectroscopy, we excite a non-radiative coherence between the discrete Landau levels of an undoped quantum well and study its dynamics. We observe quantum beats that reflect the time evolution of the coherence between the two lowest Landau level magnetoexcitons. We interpret our observations using a many-body theory and find that the inter Landau level coherence decays with a new time constant, substantially longer than the corresponding interband magnetoexciton dephasing times. Our results indicate a new intraband excitation dynamics that cannot be described in terms of uncorrelated interband excitations.

5 pages, 5 figures, to appear in Phys. Rev. B Rapid Communications

References in corpus (6)

• Stimulated and spontaneous optical generation of electron spin coherence in charged GaAs quantum dots
• Ultrafast Nonlinear Optical Response of Strongly Correlated Systems: Dynamics in the Quantum Hall Effect Regime
• Ultrafast Coulomb-induced dynamics of 2D magnetoexcitons
• Theory of ultrafast exciton dynamics in the Quantum Hall system
• Ultrafast dynamics of coherences in the quantum Hall system
• Nonlinear Optical studies of the Transient Coherence in the Quantum Hall System

Cited by in corpus (1)

• Multiple quantum beats of quantum confined exciton states in InGaAs/GaAs quantum well