Parasitic pumping currents in an interacting quantum dot

TL;DR

This paper investigates charge and spin pumping in an interacting quantum dot using non-equilibrium Green's functions, revealing parasitic currents caused by dynamical constraints, with implications for spintronics.

Contribution

It introduces a non-equilibrium Green's function approach within the time-dependent slave boson approximation to analyze parasitic pumping currents in the infinite-U regime.

Findings

Parasitic pumping currents arise from additional phases of dynamical constraints.

The behavior of pumped current varies between spin-insensitive and spin-sensitive cases.

Results have potential applications in spintronics devices.

Abstract

We analyze the charge and spin pumping in an interacting dot within the almost adiabatic limit. By using a non-equilibrium Green's function technique within the time-dependent slave boson approximation, we analyze the pumped current in terms of the dynamical constraints in the infinite-U regime. The results show the presence of parasitic pumping currents due to the additional phases of the constraints. The behavior of the pumped current through the quantum dot is illustrated in the spin-insensitive and in the spin-sensitive case relevant for spintronics applications.