title: Ubiquitous long-range antiferromagnetic coupling across the interface between superconducting and ferromagnetic oxides.
abstract: The so-called proximity effect is the manifestation, across an interface, of the systematic competition between magnetic order and superconductivity. This phenomenon has been well documented and understood for conventional superconductors coupled with metallic ferromagnets; however it is still less known for oxide materials, where much higher critical temperatures are offered by copper oxide-based superconductors. Here we show that, even in the absence of direct Cu-O-Mn covalent bonding, the interfacial CuO2 planes of superconducting La(1.85)Sr(0.15)CuO(4) thin films develop weak ferromagnetism associated to the charge transfer of spin-polarised electrons from the La(0.66)Sr(0.33)MnO(3) ferromagnet. Theoretical modelling confirms that this effect is general to all cuprate/manganite heterostructures and the presence of direct bonding only affects the strength of the coupling. The Dzyaloshinskii-Moriya interaction, also at the origin of the weak ferromagnetism of bulk cuprates, propagates the magnetisation from the interface CuO2 planes into the superconductor, eventually depressing its critical temperature.
authors.affiliation: CNR-SPIN and Dipartimento di Fisica Università di Napoli 'Federico II', Complesso Universitario di Monte Sant'Angelo, via Cinthia, Napoli I-80126, Italy.
authors.forename: G M
authors.initials: GM
authors.lastname: De Luca
authors.affiliation: CNR-SPIN and Dipartimento di Fisica Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano I-20133, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ghiringhelli
authors.affiliation: CNR-SPIN and Dipartimento di Fisica Università di Napoli 'Federico II', Complesso Universitario di Monte Sant'Angelo, via Cinthia, Napoli I-80126, Italy.
authors.forename: C A
authors.initials: CA
authors.lastname: Perroni
authors.affiliation: CNR-SPIN and Dipartimento di Fisica Università di Napoli 'Federico II', Complesso Universitario di Monte Sant'Angelo, via Cinthia, Napoli I-80126, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Cataudella
authors.affiliation: CNR-SPIN and Dipartimento di Fisica Università di Napoli 'Federico II', Complesso Universitario di Monte Sant'Angelo, via Cinthia, Napoli I-80126, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Chiarella
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831, USA.
authors.forename: C
authors.initials: C
authors.lastname: Cantoni
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Lupini
authors.affiliation: European Synchrotron Radiation Facility, 6 rue Jules Horowitz, B.P. 220, Grenoble Cedex F-38043, France.
authors.forename: N B
authors.initials: NB
authors.lastname: Brookes
authors.affiliation: Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, Enschede 7500 AE, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Huijben
authors.affiliation: Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, Enschede 7500 AE, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Koster
authors.affiliation: Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, Enschede 7500 AE, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Rijnders
authors.affiliation: CNR-SPIN and Dipartimento di Fisica Università di Napoli 'Federico II', Complesso Universitario di Monte Sant'Angelo, via Cinthia, Napoli I-80126, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Salluzzo