Pumped pure spin current and shot noise spectra in a two-level Rashba dot

Abstract

The authors analyze theoretically the pumped spin current and current noise spectra in a two-level Rashba dot connected to two ferromagnetic electrodes with parallel magnetic configuration. It is found that the interlevel spin flips induced by the Rashba spin-orbit interaction can generate a pure spin current, whose strength is determined by both the energy spacing between two levels and the spin-flip strength. It is further pointed out that the total charge current noise at a finite bias voltage can be used to determine whether the pumped current is a pure spin type or not.