Spintromechanics of a Magnetic Nanoshuttle

TL;DR

This paper theoretically explores a magnetic nanoelectromechanical device that acts as a highly efficient spin filter by leveraging spin-dependent mechanical displacements, achieving near 100% spin polarization under certain conditions.

Contribution

It introduces the concept of spin polarons in a NEM-SET device and demonstrates their potential for highly effective spin filtering controlled by voltages.

Findings

Spin-dependent mechanical displacements lead to spin polarization.

Near 100% spin polarization achievable at low voltages and temperatures.

Strong magnetic exchange forces induce spin polarons.

Abstract

We investigate theoretically the prospects for using a magnetic nanoelectromechanical single-electron tunneling (NEM-SET) device as an electronic spin filter. We find that strong magnetic exchange forces on the net spin of the mobile central dot of the NEM-SET structure lead to spin-dependent mechanical displacements ("spin polarons"), which give rise to vastly different tunnelling probabilities for electrons of different spin. The resulting spin polarization of the current can be controlled by bias and gate voltages and be very close to 100% at voltages and temperatures below a characteristic correlation energy set by the sum of the polaronic and Coulomb blockade energies.