Signature of a highly spin polarized resonance state at Co2MnSi(001)/Ag(001) interfaces

TL;DR

This study reveals a highly spin polarized surface resonance at Co2MnSi(001)/Ag(001) interfaces, identified through high energy x-ray photoemission spectroscopy, which could be crucial for spintronic applications.

Contribution

It is the first to directly observe a highly spin polarized resonance state at Co2MnSi(001)/Ag(001) interfaces using HAXPES, linking spectral features to interface states.

Findings

Spectral shoulder feature near Fermi edge in Co2MnSi/Ag interface

Feature is suppressed in other metallic interfaces

Identified as a spin polarized surface resonance

Abstract

We investigated interfaces of halfmetallic Co2MnSi(100) Heusler thin films with Ag(100), Cr(100), Cu and Al layers relevant for spin valves by high energy x-ray photoemission spectroscopy (HAXPES). Experiments on Co2MnSi samples with an Ag(100) interface showed a characteristic spectral shoulder feature close to the Fermi edge, which is strongly diminished or suppressed at Co2MnSi (100) interfaces with the other metallic layers. This feature is found to be directly related to the Co2MnSi(100) layer, as reflected by control experiments with reference non-magnetic films, i.e. without Heusler layer. By comparison with HAXPES calculations, the shoulder feature is identified as originating from an interface state related to a highly spin polarized surface resonance of Co2MnSi (100).