We predict that pure spin current flowing through the transverse leads of quantumcoherent two-dimensional electron gas (2DEG), which is induced by conventional unpolarized charge current driven through the longitudinal leads, can be tuned by the Rashba spin-orbit (SO) interaction and will decay only when disorder is sufficiently strong (but before electrons become localized). Furthermore, the p...

Edge states of the quantum Hall fluid provide an opportunity to study mesoscopic effects in a highly correlated electron system that is both experimentally accessible and theoretically tractable. In this paper we review recent work on the persistent current and Aharonov-Bohm magnetoconductance oscillations in the fractional quantum Hall effect regime.