Modulation of the dephasing time for a magnetoplasma in a quantum well

TL;DR

This paper studies femtosecond dephasing in a 2D magneto-plasma within a quantum well, revealing how magnetic field and carrier density influence dephasing times through Coulomb scattering effects.

Contribution

It extends previous models by including four Landau subbands and analyzing the dependence of dephasing on magnetic field and detuning in a magneto-plasma.

Findings

Strong modulation of dephasing time with magnetic field and carrier density.

Dephasing times are significantly affected by Coulomb scattering without screening.

Extension of earlier models to lower magnetic fields with additional Landau subbands.

Abstract

We investigate the femtosecond kinetics of optically excited 2D magneto-plasma. We calculate the femtosecond dephasing and relaxation kinetics of the laser pulse excited magneto-plasma due to bare Coulomb potential scattering, because screening is under these conditions of minor importance. By taking into account four Landau subbands in both the conduction band and the valence band, we are now able to extend our earlier study [Phys. Rev. B {\bf 58}, 1998,in print (see also cond-mat/9808073] to lower magnetic fields. We can also fix the magnetic field and change the detuning to further investigate the carrier density-dependence of the dephasing time. For both cases, we predict strong modulation in the dephasing time.