title: Tunable spin polarization and superconductivity in engineered oxide interfaces.
abstract: Advances in growth technology of oxide materials allow single atomic layer control of heterostructures. In particular delta doping, a key materials' engineering tool in today's semiconductor technology, is now also available for oxides. Here we show that a fully electric-field-tunable spin-polarized and superconducting quasi-2D electron system (q2DES) can be artificially created by inserting a few unit cells of delta doping EuTiO3 at the interface between LaAlO3 and SrTiO3 oxides. Spin polarization emerges below the ferromagnetic transition temperature of the EuTiO3 layer (TFM = 6-8 K) and is due to the exchange interaction between the magnetic moments of Eu-4f and of Ti-3d electrons. Moreover, in a large region of the phase diagram, superconductivity sets in from a ferromagnetic normal state. The occurrence of magnetic interactions, superconductivity and spin-orbit coupling in the same q2DES makes the LaAlO3/EuTiO3/SrTiO3 system an intriguing platform for the emergence of novel quantum phases in low-dimensional materials.
authors.affiliation: Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.|CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Stornaiuolo
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA.
authors.forename: C
authors.initials: C
authors.lastname: Cantoni
authors.affiliation: Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.|CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: G M
authors.initials: GM
authors.lastname: De Luca
authors.affiliation: Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.|CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Di Capua
authors.affiliation: Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.|CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: E
authors.identifier: http://orcid.org/0000-0003-4231-9776
authors.initials: E
authors.lastname: Di Gennaro
authors.affiliation: CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
authors.forename: G
authors.identifier: http://orcid.org/0000-0003-0867-7748
authors.initials: G
authors.lastname: Ghiringhelli
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS, Université Montpellier 2, F-34095 Montpellier, France.
authors.forename: B
authors.initials: B
authors.lastname: Jouault
authors.affiliation: CNR-SPIN and Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, I-14146 Genova, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Marrè
authors.affiliation: Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.|CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: D
authors.identifier: http://orcid.org/0000-0001-5740-0054
authors.initials: D
authors.lastname: Massarotti
authors.affiliation: CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Miletto Granozio
authors.affiliation: CNR-SPIN and Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, I-14146 Genova, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Pallecchi
authors.affiliation: Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Piamonteze
authors.affiliation: Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Rusponi
authors.affiliation: CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.|Dipartimento di Ingegneria dell'Informazione, Seconda Università degli Studi di Napoli (SUN), 81031 Aversa (CE), Italy.
authors.forename: F
authors.initials: F
authors.lastname: Tafuri
authors.affiliation: CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-8372-6963
authors.initials: M
authors.lastname: Salluzzo
mesh_terms: D016880:Anisotropy; D060526:Magnetic Fields; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*
chemical_list: D008670:Metals; D010087:Oxides