Influence of spin waves on transport through a quantum-dot spin valve

TL;DR

This paper explores how spin waves affect electron transport in a quantum-dot spin valve, revealing phenomena like conductance peaks, spin-polarized currents, and noise characteristics influenced by magnon interactions.

Contribution

It introduces the impact of spin waves on transport properties, including conductance, noise, and spin polarization, in a quantum-dot spin valve with noncollinear magnetizations.

Findings

Side peaks in differential conductance due to spin wave emission and absorption

Magnon-assisted tunneling can produce fully spin-polarized current without bias

Magnonic effects influence the finite-frequency Fano factor and exchange field

Abstract

We study the influence of spin waves on transport through a single-level quantum dot weakly coupled to ferromagnetic electrodes with noncollinear magnetizations. Side peaks appear in the differential conductance due to emission and absorption of spin waves. We, furthermore, investigate the nonequilibrium magnon distributions generated in the source and drain lead. In addition, we show how magnon-assisted tunneling can generate a fullly spin-polarized current without an applied transport voltage. We discuss the influence of spin waves on the current noise. Finally, we show how the magnonic contributions to the exchange field can be detected in the finite-frequency Fano factor.