| This thesis deals with two problems concerning electrons in semiconductors. The first one is that of Zero Resistance States that are observed in microwave-irradiated quantum Hall gases. In chapters 2 and 3 we introduce the framework for analyzing the statics of problem, consider the effects of disorder and discuss the kinds of domain configurations one might see. In Chapter 4 we speculate on the dynamics that the inhomogeneities in Hall conductivity might induce in a Zero Resistance State. Chapter 5 is dedicated to the second problem, that of analyzing an experiment from the field of spin Hall physics, where the spin accumulation has been seen away from the boundary. While the spins observed in experiments are found to come from the boundary, the possibility of spins generated in the bulk is considered and the appropriate experimental setup is suggested. |
