Adiabatic quantum pumping of a desired ratio of spin current to charge current

TL;DR

This paper introduces a method for generating controllable spin and charge currents using adiabatic quantum pumping in a one-dimensional conductor, with a focus on achieving specific spin-to-charge current ratios.

Contribution

It provides a new prescription for creating pure spin or spin-selective currents without relying on scattering matrices, and demonstrates the ability to produce any desired spin-to-charge current ratio.

Findings

Maximum pumped spin of 2 units achieved.

Reversal of current direction with small cycle changes.

Any ratio of spin to charge current can be produced.

Abstract

We present a prescription for generating pure spin current or spin selective current, based on adiabatic quantum pumping in a tight-binding model of a one dimensional conductor. A formula for the instantaneous pumped current is derived without introducing the scattering matrix. Our calculations indicate that some pumping cycles produce the maximum value 2 of pumped spin while others reverse the direction of current as a result of small alterations of the pumping cycle. We find pumping cycles which produce essentially any ratio of spin current to charge current.