Spin relaxation in small two-dimensional systems

The relaxation of the electron spin in a small two-dimensional system has been analyzed. It has been shown that the spin relaxation rate in such a system can be parametrically small compared to the relaxation rate in an infinite two-dimensional system and the relaxation rates for different spin components are parametrically different. The system under consideration is intermediate between the infinite two-dimensional system and quantum dot and can exhibit both classical and quantum behaviors. The applicability limit of the classical description, as well as a temperature dependent correction to the spin relaxation rate that is associated with quantum interference effects, has been determined.