Monitoring surface resonances on Co2MnSi(100) by spin-resolved photoelectron spectroscopy

Abstract

The magnitude of the spin polarization at the Fermi level of ferromagnetic materials at room temperature is a key property for spintronics. Investigating the Heusler compound Co${}_2$MnSi a value of 93$\%$ for the spin polarization has been observed at room temperature, where the high spin polarization is related to a stable surface resonance in the majority band extending deep into the bulk. In particular, we identified in our spectroscopical analysis that this surface resonance is embedded in the bulk continuum with a strong coupling to the majority bulk states. The resonance behaves very bulk-like, as it extends over the first six atomic layers of the corresponding (001)-surface. Our study includes experimental investigations, where the bulk electronic structure as well as surface-related features have been investigated using spin-resolved photoelectron spectroscopy (SR-UPS) and for a larger probing depth spin-integrated high energy x-ray photoemission spectroscopy (HAXPES). The results are interpreted in comparison with first-principles band structure and photoemission calculations which consider all relativistic, surface and high-energy effects properly.

arXiv comment9 pages, 8 figures, Heusler alloy, electronic structure and photoemission

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Cited by in corpus (7)

• Spin-polarized Weyl cones and gigantic anomalous Nernst effect in ferromagnetic Heusler films
• Direct evidence for minority spin gap in the Co2MnSi Heusler alloy
• Band structure tuning of Heusler compounds revisited: Spin- and momentum-resolved electronic structure analysis of compounds with different band filling
• Surface resonance of the Heusler half metal Co2MnSi probed by SX-ARPES
• Interface spin polarization of the Heusler compound Co2MnSi probed by unidirectional spin Hall magnetoresistance
• Spin- and time-resolved photoelectron spectroscopy and diffraction studies using time-of-flight momentum microscopes
• Signature of a highly spin polarized resonance state at Co2MnSi(001)/Ag(001) interfaces