Spin-transfer torque on a single magnetic adatom

TL;DR

This paper demonstrates theoretically how spin-polarized electrons can control and reverse the magnetic orientation of a single adatom via spin-assisted inelastic tunneling, with observable effects on tunneling conductance.

Contribution

It introduces a theoretical model showing how spin-polarized currents can manipulate a single magnetic adatom's orientation in STM setups.

Findings

Magnetic adatom orientation can be reversed by spin-polarized current.

Reversal time scales range from nanoseconds to microseconds.

Magnetization changes are detectable through tunneling conductance variations.

Abstract

We theoretically show how the spin orientation of a single magnetic adatom can be controlled by spin polarized electrons in a scanning tunneling microscope configuration. The underlying physical mechanism is spin assisted inelastic tunneling. By changing the direction of the applied current, the orientation of the magnetic adatom can be completely reversed on a time scale that ranges from a few nanoseconds to microseconds, depending on bias and temperature. The changes in the adatom magnetization direction are, in turn, reflected in the tunneling conductance.