Spin-Polarized Standing Waves in the Fermi Surface of a Ferromagnetic Thin Film

TL;DR

This study investigates spin-dependent electron reflection in Fe/W(110) films, revealing that majority spin states form quantum well states due to interface reflection, influenced by the Fermi surface topology, highlighting Fe/W as an effective spin filter.

Contribution

It demonstrates spin-selective standing wave formation in ferromagnetic thin films and links the effect to Fermi surface topology, providing insights into spin-dependent quantum well states.

Findings

Majority spin states form intense quantum well states.

Spin polarization is linked to Fermi surface topology.

Fe/W interface is effective for spin filtering.

Abstract

The spin-selective electron reflection at a ferromagnetic-paramagnetic interface is investigated using Fe films on a W(110) substrate. Angle-resolved photoemission of the majority and minority Fermi surfaces of the Fe film is used to probe standing wave formation. Intense quantum well states resulting from interfacial reflection are observed exclusively for majority states. Such high spin polarization is explained by the Fermi surface topology of the connecting substrate, and we argue that Fe/W is a particularly suitable interface for that purpose.