Spintronics-based mesoscopic heat engine

TL;DR

This paper explores a spintronics-based nanowire heat engine where temperature differences induce counterintuitive mechanical vibrations and effective temperature changes, revealing novel thermomechanical effects in spin-polarized systems.

Contribution

It demonstrates how a nonuniform magnetic field and spin-polarized leads can produce unique thermomechanical behaviors, including effective temperature reduction and vibration generation.

Findings

Stationary distribution has Boltzmann form with reduced effective temperature.

Temperature gradient reversal induces mechanical vibrations.

Counterintuitive thermal effects in spin-polarized nanowire systems.

Abstract

We consider a nanowire suspended on two spin-polarized leads and subject to a nonuniform magnetic field. We show that in such a system a temperature drop between leads can significantly affect the nanowire dynamics. In particular, it is demonstrated that under certain conditions the stationary distribution of the mechanical subsystem has Boltzmann form with effective temperature which is smaller than the temperature of the "cold" lead; this seems rather counterintuitive. We also find that the change of the direction of the temperature gradient results in generation of mechanical vibrations rather than heating of the mechanical subsystem.