Superconductor sandwiches: cuprate-manganite multilayers with a remarkable new ground state

A remarkable new electronic ground-state of a high-temperature superconductor oxide (YBa2Cu3O7−δ) is found when it is grown in-between layers of a specific manganite (Pr0.5La0.2Ca0.3MnO3). The superconductor in these ‘superconductor sandwiches’ apparently adopts an exotic granular-state due to an interaction with the manganite. Uniquely, a strong magnetic field recovers a more ‘customary’ superconducting state. Here we show how Raman spectroscopy, state-of-the-art THz ellipsometry, and transport measurements are being used to reveal the nature of this new ground-state. These measurements are shedding light on how the manganite and superconductor layers interact to cause such novel behaviour, however the exact mechanism remains unknown.

[1]  M. R. Norman,et al.  From quantum matter to high-temperature superconductivity in copper oxides , 2015, Nature.

[2]  Masanori Hangyo,et al.  Measurement of the dielectric constant of thin films by terahertz time-domain spectroscopic ellipsometry. , 2011, Optics letters.

[3]  A. Hoffmann,et al.  Giant magnetoresistance in ferromagnet/superconductor superlattices. , 2005, Physical review letters.

[4]  J. Cezar,et al.  Magnetism at the interface between ferromagnetic and superconducting oxides , 2006 .

[5]  Hole redistribution across interfaces in superconducting cuprate superlattices , 2008 .

[6]  V. Gantmakher,et al.  Superconductor–insulator quantum phase transition , 2010, 1004.3761.

[7]  Y. Tomioka,et al.  Colossal magnetoresistive manganites , 1999 .

[8]  Y. Tokura,et al.  Raman spectroscopy of the charge-orbital ordering in layered manganites , 2000 .

[9]  A. Andrés,et al.  Raman phonons and the Jahn–Teller transition in RMnO3 manganites , 2001 .

[10]  D. Satapathy,et al.  Pulsed laser deposition growth of heteroepitaxial YBa2Cu3O7/La0.67Ca0.33MnO3 superlattices on NdGaO3 and Sr0.7La0.3Al0.65Ta0.35O3 substrates , 2011, 1110.4173.

[11]  Matacotta,et al.  Jahn-teller dynamics in charge-ordered manganites from raman spectroscopy , 2000, Physical review letters.

[12]  M. L. Tacon,et al.  Lattice dynamical signature of charge density wave formation in underdoped YBa 2 Cu 3 O 6 + x , 2013, 1312.1082.

[13]  N. Kolev,et al.  Raman spectroscopy of the charge- and orbital-ordered state in La 0.5 Ca 0.5 MnO 3 , 2001 .

[14]  L. Balicas,et al.  Superconductivity in an organic insulator at very high magnetic fields. , 2001, Physical Review Letters.

[15]  Jungseek Hwang.  Electron–boson spectral density function of correlated multiband systems obtained from optical data: Ba0.6K0.4Fe2As2 and LiFeAs , 2016, Journal of physics. Condensed matter : an Institute of Physics journal.

[16]  A. Goldman,et al.  Magnetic-field-induced superconducting state in Zn nanowires driven in the normal state by an electric current. , 2009, Physical review letters.

[17]  S. Maekawa,et al.  Superconducting phase transitions in rare-earth compounds , 1978 .

[18]  A. Yamanaka,et al.  Superconductivity-induced effects on phononic and electronic Raman scattering in twin-free YBa 2 Cu 3 O 7-x single crystals , 2000 .

[19]  Yoshinori Tokura,et al.  Critical features of colossal magnetoresistive manganites , 2006 .

[20]  M. Tokumoto,et al.  Magnetic-field-induced superconductivity in a two-dimensional organic conductor , 2001, Nature.

[21]  D. Satapathy,et al.  Magnetic proximity effect in YBa2Cu3O7/La(2/3)Ca(1/3)MnO3 and YBa2Cu3O7/LaMnO(3+δ) superlattices. , 2011, Physical review letters.

[22]  A. Goldman.  SUPERCONDUCTOR-INSULATOR TRANSITIONS , 2010 .

[23]  M. Peter,et al.  ULTRA-HIGH-FIELD SUPERCONDUCTIVITY , 1962 .

[24]  M. Varela,et al.  Granular superconductivity and magnetic-field-driven recovery of macroscopic coherence in a cuprate/manganite multilayer , 2015, 1512.03263.

[25]  C. Thomsen,et al.  Raman spectroscopy of orthorhombic perovskitelike YMnO_{3} and LaMnO_{3} , 1998 .

[26]  C. Rossel,et al.  Observation of Magnetic-Field-Induced Superconductivity , 1984 .

[27]  Y. Okimoto,et al.  Critical control of competition between metallic ferromagnetism and charge/orbital correlation in single crystals of perovskite manganites , 2003 .

[28]  J. Humlíček,et al.  Far-infrared ellipsometry using a synchrotron light source - the dielectric response of the cuprate high Tc superconductors , 2004 .

[29]  H. Habermeier,et al.  Long-range transfer of electron-phonon coupling in oxide superlattices. , 2012, Nature materials.

[30]  C. Bernhard,et al.  Terahertz ellipsometry study of the soft mode behavior in ultrathin SrTiO3 films , 2015, 1511.04521.