DISSIPATIVE STEADY-STATE SPATIAL ORDERING IN PHOTOEXCITED POLAR SEMICONDUCTORS

Abstract

We consider the question of formation of patterned dissipative structures in condensed matter under high levels of excitation. The case of n-doped direct-gap polar semiconductors under continuous laser illumination is studied. We show that the solution consisting of the homogeneous population of electrons and holes, that develops from the equilibrium state with increasing values of the laser power flux, presents a bifurcation point. A new solution emerges from it corresponding to the formation of a steady-state spatially organized structure in the carrier charge density in the form of a polarization wave. This dissipative structure occurs beyond a critical distance from equilibrium, when a fluctuation drives the carrier system to such self-organized macroscopically ordered state. It is stabilized by the joint action of collective and dissipative effects.