Weakly-Correlated nature of ferromagnetism in nonsymmorphic CrO2 revealed by bulk-sensitive soft-X-ray ARPES
Bisti, Federico (ALBA Laboratori de Llum de Sincrotró)
Rogalev, Victor A. (Paul Scherrer Institut (Suïssa))
Karolak, Michael (Universität Würzburg)
Paul, S. (University of Alabama)
Gupta, Arunava (University of Alabama)
Schmitt, Thorsten (Paul Scherrer Institut (Suïssa))
Güntherodt, G. (RWTH Aachen University)
Eyert, Volker (Materials Design SARL)
Sangiovanni, Giorgio (Universität Würzburg)
Profeta, Gianni (CNR-SPIN L'Aquila)
Strocov, Vladimir N. (Paul Scherrer Institut (Suïssa))

Fecha:	2017
Resumen:	Chromium dioxide CrO belongs to a class of materials called ferromagnetic half-metals, whose peculiar aspect is that they act as a metal in one spin orientation and as a semiconductor or insulator in the opposite one. Despite numerous experimental and theoretical studies motivated by technologically important applications of this material in spintronics, its fundamental properties such as momentum-resolved electron dispersions and the Fermi surface have so far remained experimentally inaccessible because of metastability of its surface, which instantly reduces to amorphous CrO. In this work, we demonstrate that direct access to the native electronic structure of CrO can be achieved with soft-x-ray angle-resolved photoemission spectroscopy whose large probing depth penetrates through the CrO layer. For the first time, the electronic dispersions and Fermi surface of CrO are measured, which are fundamental prerequisites to solve the long debate on the nature of electronic correlations in this material. Since density functional theory augmented by a relatively weak local Coulomb repulsion gives an exhaustive description of our spectroscopic data, we rule out strong-coupling theories of CrO. Crucial for the correct interpretation of our experimental data in terms of the valence-band dispersions is the understanding of a nontrivial spectral response of CrO caused by interference effects in the photoemission process originating from the nonsymmorphic space group of the rutile crystal structure of CrO.
Ayudas:	European Commission 290605
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Angle resolved photoemission spectroscopy ; Coulomb repulsions ; Electronic correlation ; Electronic dispersions ; Fundamental properties ; Interference effects ; Photoemission process ; Spectroscopic data
Publicado en:	Physical Review, Vol. 7, Issue 4 (December 2017) , art. 041067, ISSN 2160-3308

DOI: 10.1103/PhysRevX.7.041067

14 p, 3.2 MB

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Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > El Sincrotrón ALBA
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