Abstract
A quantum pump device involving magnetic barriers produced by the deposition of ferromagnetic stripes on heterostructures is investigated. The device for dc transport does not provide spin-polarized currents, but in the adiabatic regime, when one modulates two independent parameters of this device, spin-up and spin-down electrons are driven in opposite directions, with the net result being that a finite net spin current is transported with negligible charge current. We also analyze our proposed device for inelastic scattering and spin-orbit scattering. Strong spin-orbit scattering and more so inelastic scattering have a somewhat detrimental effect on spin/charge ratio especially in the strong pumping regime. Further we show our pump to be almost noiseless, implying an optimal quantum spin pump.
- Received 14 October 2003
DOI:https://doi.org/10.1103/PhysRevB.69.085318
©2004 American Physical Society