title: Anisotropic magnetoresistance in an antiferromagnetic semiconductor.
abstract: Recent studies in devices comprising metal antiferromagnets have demonstrated the feasibility of a novel spintronic concept in which spin-dependent phenomena are governed by an antiferromagnet instead of a ferromagnet. Here we report experimental observation of the anisotropic magnetoresistance in an antiferromagnetic semiconductor Sr2IrO4. Based on ab initio calculations, we associate the origin of the phenomenon with large anisotropies in the relativistic electronic structure. The antiferromagnet film is exchange coupled to a ferromagnet, which allows us to reorient the antiferromagnet spin-axis in applied magnetic fields via the exchange spring effect. We demonstrate that the semiconducting nature of our AFM electrode allows us to perform anisotropic magnetoresistance measurements in the current-perpendicular-to-plane geometry without introducing a tunnel barrier into the stack. Temperature-dependent measurements of the resistance and anisotropic magnetoresistance highlight the large, entangled tunabilities of the ordinary charge and spin-dependent transport in a spintronic device utilizing the antiferromagnet semiconductor.
authors.affiliation: 1] Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, E-08193 Barcelona, Spain [2] Experimental Department II, Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Fina
authors.affiliation: 1] Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA [2] Centre d'Investigació en Nanociència i Nanotecnologia (CIN2), CSIC-ICN, 08193 Barcelona, Spain [3] Department of Spintronics and Nanoelectronics, Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic.
authors.forename: X
authors.initials: X
authors.lastname: Marti
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: D
authors.initials: D
authors.lastname: Yi
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Chu
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: C
authors.initials: C
authors.lastname: Rayan-Serrao
authors.affiliation: National Center for Electron Microscopy, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: S
authors.initials: S
authors.lastname: Suresha
authors.affiliation: Department of Condensed Matter Theory, Institute of Physics ASCR, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic.
authors.forename: A B
authors.initials: AB
authors.lastname: Shick
authors.affiliation: Department of Spintronics and Nanoelectronics, Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Zelezný
authors.affiliation: 1] Department of Spintronics and Nanoelectronics, Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic [2] School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: T
authors.initials: T
authors.lastname: Jungwirth
authors.affiliation: Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, E-08193 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Fontcuberta
authors.affiliation: 1] Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA [2] Department of Physics, University of California, Berkeley, California 94720, USA [3] National Center for Electron Microscopy, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA [4].
authors.forename: R
authors.initials: R
authors.lastname: Ramesh