title: Superconductor to Mott insulator transition in YBa2Cu3O7/LaCaMnO3 heterostructures.
abstract: The superconductor-to-insulator transition (SIT) induced by means such as external magnetic fields, disorder or spatial confinement is a vivid illustration of a quantum phase transition dramatically affecting the superconducting order parameter. In pursuit of a new realization of the SIT by interfacial charge transfer, we developed extremely thin superlattices composed of high Tc superconductor YBa2Cu3O7 (YBCO) and colossal magnetoresistance ferromagnet La0.67Ca0.33MnO3 (LCMO). By using linearly polarized resonant X-ray absorption spectroscopy and magnetic circular dichroism, combined with hard X-ray photoelectron spectroscopy, we derived a complete picture of the interfacial carrier doping in cuprate and manganite atomic layers, leading to the transition from superconducting to an unusual Mott insulating state emerging with the increase of LCMO layer thickness. In addition, contrary to the common perception that only transition metal ions may respond to the charge transfer process, we found that charge is also actively compensated by rare-earth and alkaline-earth metal ions of the interface. Such deterministic control of Tc by pure electronic doping without any hindering effects of chemical substitution is another promising route to disentangle the role of disorder on the pseudo-gap and charge density wave phases of underdoped cuprates.
authors.affiliation: Department of Physics, University of Arkansas, Fayetteville, Arkansas 70701, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Gray
authors.affiliation: Department of Physics, University of Arkansas, Fayetteville, Arkansas 70701, USA.
authors.forename: S
authors.initials: S
authors.lastname: Middey
authors.affiliation: Department of Physics, University of California, Davis, California 95616, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley 94720, USA.
authors.forename: G
authors.initials: G
authors.lastname: Conti
authors.affiliation: Department of Physics, Temple University, Philadelpia, Pennsylvania 19130, USA.
authors.forename: A X
authors.initials: AX
authors.lastname: Gray
authors.affiliation: Department of Physics, University of California, Davis, California 95616, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley 94720, USA.
authors.forename: C-T
authors.initials: CT
authors.lastname: Kuo
authors.affiliation: Oerlikon Leybold Vacuum GmbH, Köln, Germany.
authors.forename: A M
authors.initials: AM
authors.lastname: Kaiser
authors.affiliation: Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ueda
authors.affiliation: Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Physics, University of Arkansas, Fayetteville, Arkansas 70701, USA.
authors.forename: D
authors.initials: D
authors.lastname: Meyers
authors.affiliation: Department of Physics, University of Arkansas, Fayetteville, Arkansas 70701, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kareev
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.|Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: I C
authors.initials: IC
authors.lastname: Tung
authors.affiliation: Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Physics, University of California, Davis, California 95616, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley 94720, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Fadley
authors.affiliation: Department of Physics, University of Arkansas, Fayetteville, Arkansas 70701, USA.|Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chakhalian
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Freeland