Absence of Magnetic Proximity Effect at the Interface of Bi2Se3 and (Bi,Sb)2Te3 with EuS

A. i. Figueroa (1) , Frédéric Bonell (1) , M. g. Cuxart (1, 2) , M. Valvidares (3) , P. Gargiani (3) , G. van Der Laan (4) , A. Mugarza (1, 5) , S. o. Valenzuela (1, 5)

1 ICN2 - ICN2 - Institut Catala de Nanociencia i Nanotecnologia
2 UAB - Universitat Autònoma de Barcelona = Autonomous University of Barcelona = Universidad Autónoma de Barcelona
3 ALBA Synchrotron light source [Barcelone]
4 DIAMOND Light source
5 ICREA - Institució Catalana de Recerca i Estudis Avançats = Catalan Institution for Research and Advanced Studies

We performed x-ray magnetic circular dichroism (XMCD) measurements on heterostructures comprising topological insulators (TIs) of the (Bi,Sb)2(Se,Te)3 family and the magnetic insulator EuS. XMCD measurements allow us to investigate element-selective magnetic proximity effects at the very TI/EuS interface. A systematic analysis reveals that there is neither significant induced magnetism within the TI nor an enhancement of the Eu magnetic moment at such interface. The induced magnetic moments in Bi, Sb, Te, and Se sites are lower than the estimated detection limit of the XMCD measurements of ∼10−3 μB/at.

Domaines: Physique [physics]

A. i. Figueroa, Frédéric Bonell, M. g. Cuxart, M. Valvidares, P. Gargiani, et al.. Absence of Magnetic Proximity Effect at the Interface of Bi2Se3 and (Bi,Sb)2Te3 with EuS. Physical Review Letters, 2020, 125 (22), ⟨10.1103/PhysRevLett.125.226801⟩. ⟨hal-03030494⟩