O ct 1 99 9 Electronic Dephasing in the Quantum Hall Regime
نویسندگان
چکیده
By means of degenerate four-wave mixing (FWM), we investigate the quantum coherence of electron-hole pairs in the presence of a two-dimensional electron gas in modulation–doped GaAs-AlGaAs quantum wells in the quantum Hall effect regime. With increasing magnetic field, we observe a crossover from Markovian to non–Markovian behavior, as well as large jumps in the decay time of the FWM signal at even Landau level filling factors. The main observations can be qualitatively reproduced by a model which takes into account scattering by the collective excitations of the two-dimensional electron gas.
منابع مشابه
ar X iv : g r - qc / 9 71 00 20 v 1 3 O ct 1 99 7 THE RELIABILITY HORIZON
The " reliability horizon " for semi-classical quantum gravity quantifies the extent to which we should trust semi-classical quantum gravity, and gives a handle on just where the " Planck regime " resides. The key obstruction to pushing semi-classical quantum gravity into the Planck regime is often the existence of large metric fluctuations, rather than a large back-reaction.
متن کامل2 9 O ct 1 99 7 Charge and current oscillations in Fractional quantum Hall systems with edges
Stationary solutions of the Chern-Simons effective field theory for the fractional quantum Hall systems with edges are presented for Hall bar, disk and annulus. In the infinitely long Hall bar geometry (non compact case), the charge density is shown to be monotonic inside the sample. In sharp contrast, spatial oscillatory modes of charge density are found for the two circular geometries, which ...
متن کاملOn the dephasing time of the chiral metal
– In the low-dimensional disordered systems the dephasing time and the inelastic scattering (out-scattering) time are in general different. We show that in the case of the two-dimensional chiral metal which is formed at the surface of a layered three dimensional system, which is exhibiting the integer quantum Hall effect these two quantities are essentially the same and their temperature-depend...
متن کاملar X iv : c on d - m at / 9 90 81 05 v 4 4 O ct 1 99 9 Coherent Ultrafast Optical Dynamics of the Fermi Edge Singularity
We develop a non–equilibrium many–body theory of the coherent femtosec-ond nonlinear optical response of the Fermi edge singularity. We study the role of the dynamical Fermi sea response in the time–evolution of the pump–probe spectra. The electron–hole correlations are treated nonperturbatively with the time–dependent coupled cluster expansion combined with the effective Hamil-tonian approach....
متن کامل