Complete spin polarization of electrons in semiconductor layers and quantum dots

TL;DR

This paper demonstrates that non-equilibrium electrons in semiconductor layers and quantum dots can be fully spin polarized through electrical injection and extraction using ferromagnetic contacts, with potential applications in spintronics and quantum info.

Contribution

It introduces a method to achieve complete electron spin polarization in nonmagnetic semiconductor structures via electrical means with ferromagnetic contacts.

Findings

Full spin polarization achieved in semiconductor layers and quantum dots.

Sign of polarization controlled by current direction.

Potential applications in spintronics and quantum information processing.

Abstract

We demonstrate that non-equilibrium electrons in thin nonmagnetic semiconductor layers or quantum dots can be fully spin polarized by means of simultaneous electrical spin injection and extraction. The complete spin polarization is achieved if the thin layers or quantum dots are placed between two ferromagnetic metal contacts with moderate spin injection coefficients and antiparallel magnetizations. The sign of the spin polarization is determined by the direction of the current. Aplications of this effect in spintronics and quantum information processing are discussed.