One of the great challenges in quantum physics is the realization of practical quantum information technology. We propose research that aims at building a memory element for optical pulses, that can preserve the quantum state of the optical pulse. It is a new approach, that investigates whether this can be accomplished with electron spins in solid-state material. This memory element is a crucial ingredient for optical quantum communication over long distances.

We proposed to use the effect of Electromagnetically Induced Transparency (EIT), which is a phenomenon which can occur in a medium with three-levels system, that have two energy states with a long coherence time, and each of these states have a strong dipole transition to a common excited state. By optically pumping one of the dipole allowed transitions, the absorption due to the second dipole transition can be eliminated due to an optically induced coherent superposition between the excited state and one of the energy states with a long coherence time. In this work we propose a scheme for EIT, which utilizes the long electron-spin coherence time in a GaAs quantum well. The tree-level system of interest is obtained by applying a high magnetic field that brings the system in the quantum Hall state with filling factor ОЅ=1. This allows for using two Zeeman split levels in the conduction band and the highest Landau level in the valence band for realizing a three-level system. We designed a system in which Landau levels in the GaAs quantum well allow us to use co-propagating cross linearly polarized laser beams for controlling EIT. The use of different polarization of control and probe light allows overcoming the spectral overlap between the optical transitions that result from inhomogeneous broadening, e.g. due to fluctuation in the width of the quantum well.