Fingerprints of the Magnetic Polaron in Nonequilibrium Electron Transport through a Quantum Wire Coupled to a Ferromagnetic Spin Chain

TL;DR

This paper investigates how magnetic polarons influence electron transport in a quantum wire coupled to a ferromagnetic spin chain, revealing coherent transport signals and conductance features affected by magnetic fields and lead polarization.

Contribution

It introduces a theoretical analysis of magnetic polaron signatures in nonequilibrium electron transport using the Keldysh formalism, highlighting the role of hybridized electron-magnon states.

Findings

Identification of conductance peaks related to magnetic polarons

Observation of coherent transport signals due to low decoherence

Dependence of conductance features on magnetic field and lead polarization

Abstract

We study nonequilibrium quantum transport through a mesoscopic wire coupled via local exchange to a ferromagnetic spin chain. Using the Keldysh formalism in the self-consistent Born approximation, we identify fingerprints of the magnetic polaron state formed by hybridization of electronic and magnon states. Because of its low decoherence rate, we find coherent transport signals. Both elastic and inelastic peaks of the differential conductance are discussed as a function of external magnetic fields, the polarization of the leads and the electronic level spacing of the wire.