Advertisement

Superconductivity in the Two-Dimensional Electron Gas at Transition Metal Oxide Interfaces

  • J. C. NieEmail author
Chapter

Abstract

The transition metal oxide interface has attracted extensive attention due to its unique, strong correlation properties. In particular, LaAlO3/SrTiO3(LAO/STO) interface has a high mobility of two-dimensional electron gas (2DEG) and specific physical phenomena such as superconductivity, ferromagnetism, and the coexistence of superconductivity and ferromagnetism are observed. Other transition metal oxide interface systems also show high mobility and similar novel quantum phenomena. Superconducting 2DEG at the LAO/STO interface offers an appealing platform for quantum phase transition from a superconductor to a weakly localized metal. Although the research on the transition metal oxide interface is extensive, there are still many outstanding unsolved issues, such as the origin of 2DEG, the superconducting pairing mechanism of 2DEG, the origin of ferromagnetism, and the coexistence of superconductivity and ferromagnetism. Considering these aspects, the 2DEG of the transition metal oxide interface is of high interest for basic research and potential applications. This chapter presents a brief state-of-the-art view of the research results on superconductivity in 2DEG based on literature and our findings.

Keywords

Transition metal oxide interface LaAlO3/SrTiO3 heterojunction Two-dimensional electron gas (2DEG) Superconductivity Interface superconductivity Ferromagnetism Coexistence of superconductivity and ferromagnetism Superconducting pairing mechanism Unconventional superconductivity p-wave superconductor Spin-triplet pairing FFLO superconductor Superconductor-insulator/metal transition 

Notes

Acknowledgments

This work is supported by the National Natural Science Foundation of China (Grants No. 11674031 and No. 11474022) and the National Basic Research Program of China (Grants No. 2014CB920903 and No. 2013CB921701) for the financial support.

References

  1. 1.
    A. Ohtomo, D.A. Muller, J.L. Grazul, H.Y. Hwang, Artificial charge-modulation in atomic-scale perovskite titanate superlattices. Nature 419(6905), 378–380 (2002)Google Scholar
  2. 2.
    S. Okamoto, A.J. Millis, Electronic reconstruction at an interface between a Mott insulator and a band insulator. Nature 428(6983), 630–633 (2004)Google Scholar
  3. 3.
    A. Ohtomo, H.Y. Hwang, A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 427(6973), 423–426 (2004)Google Scholar
  4. 4.
    A.D. Caviglia, S. Gariglio, C. Cancellieri, B. Sacepe, A. Fete, N. Reyren, M. Gabay, A.F. Morpurgo, J.-M. Triscone, Two-dimensional quantum oscillations of the conductance at LaAlO3/SrTiO3 interfaces. Phys. Rev. Lett. 105, 236802 (2010)Google Scholar
  5. 5.
    N. Nakagawa, H.Y. Hwang, D.A. Muller, Why some interfaces cannot be sharp. Nat. Mater. 5(3), 204–209 (2006)Google Scholar
  6. 6.
    G. Baraff, J.A. Appelbaum, D.R. Hamann, Self-consistent calculation of electronic-structure at an abrupt GaAs-Ge interface. Phys. Rev. Lett. 38(5), 237 (1977)Google Scholar
  7. 7.
    W.A. Harrison, E.A. Kraut, J.R. Waldrop, R.W. Grant, Polar heterojunction interfaces. Phys. Rev. B 18(8), 4402 (1978)Google Scholar
  8. 8.
    S. Thiel, G. Hammerl, A. Schmehl, C.W. Schneider, J. Mannhart, Tunable quasi-two-dimensional electron gases in oxide heterostructures. Science 313(5795), 1942–1945 (2006)Google Scholar
  9. 9.
    A. Ohtomo, H.Y. Hwang, A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 441(7089), 120–120 (2006)Google Scholar
  10. 10.
    J. Nishimura, A. Ohtomo, A. Ohkubo, Y. Murakami, M. Kawasaki, Controlled carrier generation at a polarity-discontinued perovskite heterointerface. Jpn. J. Appl. Phys. Part 2-Lett. & Express Lett. 43(8A), L1032 (2004)Google Scholar
  11. 11.
    Kwok, H. L., Charge transfer and re-distribution in the TiO 2 -SrTiO 3 heterostructure[C], IOP Conference Series-Materials Science and Engineering, IOP Publishing, 2010, 8: 012031Google Scholar
  12. 12.
    W. Siemons, G. Koster, H. Yamamoto, W. Harrison, G. Lucovsky, T. Geballe, D.H.A. Blank, M.R. Beasley, Origin of charge density at LaAlO3 on SrTiO3 heterointerfaces: Possibility of intrinsic doping. Phys. Rev. Lett. 98(19), 196802 (2007)Google Scholar
  13. 13.
    L. Qiao, T.C. Droubay, T.C. Kaspar, P.V. Sushko, S.A. Chambers, Cation mixing, band offsets and electric fields at LaAlO3/SrTiO3(001) heterojunctions with variable La:Al atom ratio. Surf. Sci. 605(15), 1381–1387 (2011)Google Scholar
  14. 14.
    P.R. Willmott, S.A. Pauli, R. Herger, C.M. Schlepuetz, D. Martoccia, B.D. Patterson, B. Delley, R. Clarke, D. Kumah, C. Cionca, Y. Yacoby, Structural basis for the conducting interface between LaAlO3 and SrTiO3. Phys. Rev. Lett. 99(15), 155502 (2007)Google Scholar
  15. 15.
    J. Mannhart, D.H.A. Blank, H.Y. Hwang, A.J. Millis, J.-M. Triscone, Two-dimensional Electron gases at oxide interfaces. MRS Bull. 33(11), 1027–1034 (2008)Google Scholar
  16. 16.
    J.A. Sulpizio, S. Ilani, P. Irvin, J. Levy, Nanoscale Phenomena in Oxide Heterostructures. Ann. Rev. Mater. Res. 44(1), 117–149 (2014)Google Scholar
  17. 17.
    M.L. Reinle-Schmitt, C. Cancellieri, D. Li, D. Fontaine, M. Medarde, E. Pomjakushina, C.W. Schneider, S. Gariglio, P. Ghosez, J.-M. Triscone, P.R. Willmott, Tunable conductivity threshold at polar oxide interfaces. Nat. Commun. 3, 932 (2012)Google Scholar
  18. 18.
    J.N. Eckstein, Oxide interfaces - watch out for the lack of oxygen. Nat. Mater. 6(7), 473 (2007)Google Scholar
  19. 19.
    G. Singh-Bhalla, C. Bell, J. Ravichandran, W. Siemons, Y. Hikita, S. Salahuddin, A. Hebard, H.Y. Hwang, R. Ramesh, Built-in and induced polarization across LaAlO3/SrTiO3 heterojunctions. Nat. Phys. 7, 80 (2011)Google Scholar
  20. 20.
    E. Breckenfeld, N. Bronn, J. Karthik, A.R. Damodaran, S. Lee, N. Mason, L.W. Martin, Effect of growth induced (non) stoichiometry on interfacial conductance in LaAlO3/SrTiO3. Phys. Rev. Lett. 110, 196804 (2013)Google Scholar
  21. 21.
    Z.Q. Liu, C.J. Li, W.M. Lu, X.H. Huang, Z. Huang, S.W. Zeng, X.P. Qiu, L.S. Huang, A. Annadi, J.S. Chen, J.M.D. Coey, T. Venkatesan, Ariando, Origin of the Two-Dimensional Electron Gas at LaAlO3/SrTiO3 Interfaces: The Role of Oxygen Vacancies and Electronic Reconstruction. Phys. Rev. X 3, 021010 (2013)Google Scholar
  22. 22.
    J. Lee, A.A. Demkov, Charge origin and localization at the n-type SrTiO3/LaAlO3 interface. Phys. Rev. B 78, 193104 (2008)Google Scholar
  23. 23.
    Y. Segal, J.H. Ngai, J.W. Reiner, F.J. Walker, C.H. Ahn, X-ray photoemission studies of the metal-insulator transition in LaAlO3/SrTiO3 structures grown by molecular beam epitaxy. Phys. Rev. B 80, 241107 (2009)Google Scholar
  24. 24.
    R. Pentcheva, W.E. Pickett, Electronic phenomena at complex oxide interfaces: Insights from first principles. J. Phys. Condens. Matter 22, 043001 (2010)Google Scholar
  25. 25.
    M. Takizawa, S. Tsuda, T. Susaki, H.Y. Hwang, A. Fujimori, Electronic charges and electric potential at LaAlO3/SrTiO3 interfaces studied by core-level photoemission spectroscopy. Phys. Rev. B 84, 245124 (2011)Google Scholar
  26. 26.
    G. Berner, A. Mueller, F. Pfaff, J. Walde, C. Richter, J. Mannhart, S. Thiess, A. Gloskovskii, W. Drube, M. Sing, R. Claessen, Band alignment in LaAlO3/SrTiO3 oxide heterostructures inferred from hard x-ray photoelectron spectroscopy. Phys. Rev. B 88, 115111 (2013)Google Scholar
  27. 27.
    M. Sing, G. Berner, K. Goss, A. Mueller, A. Ruff, A. Wetscherek, S. Thiel, J. Mannhart, S.A. Pauli, C.W. Schneider, P.R. Willmott, M. Gorgoi, F. Schaefers, R. Claessen, Profiling the Interface Electron gas of LaAlO3/SrTiO3 Heterostructures with hard X-ray photoelectron spectroscopy. Phys. Rev. Lett. 102, 176805 (2009)Google Scholar
  28. 28.
    A. Savoia, D. Paparo, P. Perna, Z. Ristic, M. Salluzzo, F.M. Granozio, U.S. di Uccio, C. Richter, S. Thiel, J. Mannhart, L. Marrucci, Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: Evidence from optical second harmonic generation. Phys. Rev. B 80, 075110 (2009)Google Scholar
  29. 29.
    Y. Mukunoki, N. Nakagawa, T. Susaki, H.Y. Hwang, Atomically flat (110) SrTiO3 and heteroepitaxy. Appl. Phys. Lett. 86, 171908 (2005)Google Scholar
  30. 30.
    G. Herranz, F. Sanchez, N. Dix, M. Scigaj, J. Fontcuberta, High mobility conduction at (110) and (111) LaAlO3/SrTiO3 interfaces. Sci. Rep. 2, 758 (2012)Google Scholar
  31. 31.
    A. Annadi, Q. Zhang, X.R. Wang, N. Tuzla, K. Gopinadhan, W.M. Lu, A.R. Barman, Z.Q. Liu, A. Srivastava, S. Saha, Y.L. Zhao, S.W. Zeng, S. Dhar, E. Olsson, B. Gu, S. Yunoki, S. Maekawa, H. Hilgenkamp, T. Venkatesan, Ariando, Anisotropic two-dimensional electron gas at the LaAlO3/SrTiO3 (110) interface. Nat. Commun. 4, 1838 (2013)Google Scholar
  32. 32.
    Y.L. Han, S.C. Shen, J. You, H.O. Li, Z.Z. Luo, C.J. Li, G.L. Qu, C.M. Xiong, R.F. Dou, L. He, D. Naugle, G.P. Guo, J.C. Nie, Two-dimensional superconductivity at (110) LaAlO3/SrTiO3 interfaces. Appl. Phys. Lett. 105, 192603 (2014)Google Scholar
  33. 33.
    G. Herranz, G. Singh, N. Bergeal, A. Jouan, J. Lesueur, J. Gazquez, M. Varela, M. Scigaj, N. Dix, F. Sanchez, J. Fontcuberta, Engineering two-dimensional superconductivity and Rashba spin-orbit coupling in LaAlO3/SrTiO3 quantum wells by selective orbital occupancy. Nat. Commun. 6, 6028 (2015)Google Scholar
  34. 34.
    A.S. Kalabukhov, Y.A. Boikov, I.T. Serenkov, V.I. Sakharov, V.N. Popok, R. Gunnarsson, J. Borjesson, N. Ljustina, E. Olsson, D. Winkler, T. Claeson, Cationic disorder and phase segregation in LaAlO3/SrTiO3 Heterointerfaces evidenced by medium-energy ion spectroscopy. Phys. Rev. Lett. 103, 146101 (2009)Google Scholar
  35. 35.
    S.A. Chambers, M.H. Engelhard, V. Shutthanandan, Z. Zhu, T.C. Droubay, L. Qiao, P.V. Sushko, T. Feng, H.D. Lee, T. Gustafsson, E. Garfunkel, A.B. Shah, J.M. Zuo, Q.M. Ramasse, Instability, intermixing and electronic structure at the epitaxial LaAlO3/SrTiO3(001) heterojunction. Surf. Sci. Rep. 65, 317 (2010)Google Scholar
  36. 36.
    L. Qiao, T.C. Droubay, T. Varga, M.E. Bowden, V. Shutthanandan, Z. Zhu, T.C. Kaspar, S.A. Chambers, Epitaxial growth, structure, and intermixing at the LaAlO3/SrTiO3 interface as the film stoichiometry is varied. Phys. Rev. B 83, 085408 (2011)Google Scholar
  37. 37.
    R. Yamamoto, C. Bell, Y. Hikita, H.Y. Hwang, H. Nakamura, T. Kimura, Y. Wakabayashi, Structural comparison of n-type and p-type LaAlO3/SrTiO3 interfaces. Phys. Rev. Lett. 107, 036104 (2011)Google Scholar
  38. 38.
    Y. Fujishima, Y. Tokura, T. Arima, S. Uchida, Optical-conductivity spectra of Sr1-xLaxTiO3-filling-dependent effect of the electron correlation. Phys. Rev. B 46, 11167 (1992)Google Scholar
  39. 39.
    M. Takizawa, H. Wadati, K. Tanaka, M. Hashimoto, T. Yoshida, A. Fujimori, A. Chikamatsu, H. Kumigashira, M. Oshima, K. Shibuya, T. Mihara, T. Ohnishi, M. Lippmaa, M. Kawasaki, H. Koinuma, S. Okamoto, A.J. Millis, Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices. Phys. Rev. Lett. 97, 057601 (2006)Google Scholar
  40. 40.
    G. Herranz, M. Basletic, M. Bibes, C. Carretero, E. Tafra, E. Jacquet, K. Bouzehouane, C. Deranlot, A. Hamzic, J.-M. Broto, A. Barthelemy, A. Fert, High mobility in LaAlO3/SrTiO3 heterostructures: Origin, dimensionality, and perspectives. Phys. Rev. Lett. 98, 216803 (2007)Google Scholar
  41. 41.
    Y.L. Han, Y.W. Fang, Z.Z. Yang, C.J. Li, L. He, S.C. Shen, Z.Z. Luo, G.L. Qu, C.M. Xiong, R.F. Dou, X. Wei, L. Gu, C.G. Duan, J.C. Nie, Reconstruction of electrostatic field at the interface leads to formation of two-dimensional electron gas at multivalent (110) LaAlO3/SrTiO3 interfaces. Phys. Rev. B 92, 115304 (2015)Google Scholar
  42. 42.
    N. Reyren, S. Thiel, A.D. Caviglia, L.F. Kourkoutis, G. Hammerl, C. Richter, C.W. Schneider, T. Kopp, A.-S. Ruetschi, D. Jaccard, M. Gabay, D.A. Muller, J.-M. Triscone, J. Mannhart, Superconducting interfaces between insulating oxides. Science 317(5842), 1196–1199 (2007)Google Scholar
  43. 43.
    G.E.D.K. Prawiroatmodjo, F. Trier, D.V. Christensen, Y. Chen, N. Pryds, T.S. Jespersen, Evidence of weak superconductivity at the room-temperature grown LaAlO3/SrTiO3 interface. Phys. Rev. B 93, 184504 (2016)Google Scholar
  44. 44.
    G. De Luca, A. Rubano, E. di Gennaro, A. Khare, F.M. Granozio, U.S. di Uccio, L. Marrucci, D. Paparo, Potential-well depth at amorphous-LaAlO3/crystalline-SrTiO3 interfaces measured by optical second harmonic generation. Appl. Phys. Lett. 104, 261603 (2014)Google Scholar
  45. 45.
    Y.Z. Chen, D.V. Christensen, F. Trier, N. Pryds, A. Smith, S. Linderoth, On the origin of metallic conductivity at the interface of LaAlO3/SrTiO3. Appl. Surf. Sci. 258, 9242–9245 (2012)Google Scholar
  46. 46.
    E. Beyreuther, D. Paparo, A. Thiessen, S. Grafstroem, L.M. Eng, Conducting and insulating LaAlO3/SrTiO3 interfaces: A comparative surface photovoltage investigation. J. Appl. Phys. 114, 243709 (2013)Google Scholar
  47. 47.
    P. Xu, Y. Ayino, C. Cheng, V.S. Pribiag, R.B. Comes, P.V. Sushko, S.A. Chambers, B. Jalan, Predictive control over charge density in the two-dimensional Electron gas at the Polar-Nonpolar NdTiO3/SrTiO3 Interface. Phys. Rev. Lett. 117, 106803 (2016)Google Scholar
  48. 48.
    M.P. Warusawithana, C. Richter, J.A. Mundy, P. Roy, J. Ludwig, S. Paetel, T. Heeg, A.A. Pawlicki, L.F. Kourkoutis, M. Zheng, M. Lee, B. Mulcahy, W. Zander, Y. Zhu, J. Schubert, J.N. Eckstein, D.A. Muller, C.S. Hellberg, J. Mannhart, D.G. Schlom, LaAlO3 stoichiometry is key to electron liquid formation at LaAlO3/SrTiO3 interfaces. Nat. Commun. 4, 2351 (2013)Google Scholar
  49. 49.
    F. Gunkel, S. Hoffmann-Eifert, R.A. Heinen, D.V. Christensen, Y.Z. Chen, N. Pryds, R. Waser, R. Dittmann, Thermodynamic ground states of complex oxide Heterointerfaces. ACS Appl. Mater. Interfaces 9, 1086–1092 (2017)Google Scholar
  50. 50.
    Y.Z. Chen, N. Pryds, J.E. Kleibeuker, G. Koster, J.R. Sun, E. Stamate, B.G. Shen, G. Rijnders, S. Linderoth, Metallic and insulating interfaces of amorphous SrTiO3-based oxide Heterostructures. Nano Lett. 11, 3774–3778 (2011)Google Scholar
  51. 51.
    S.W. Lee, Y.Q. Liu, J. Heo, R.G. Gordon, Creation and control of two-dimensional Electron gas using Al-based amorphous oxides/SrTiO3 Heterostructures grown by atomic layer deposition. Nano Lett. 12, 4775–4783 (2012)Google Scholar
  52. 52.
    C.J. Li, Y.P. Hong, H.X. Xue, X.X. Wang, Y.C. Li, K.J. Liu, W.M. Jiang, M.R. Liu, L. He, R.F. Dou, C.M. Xiong, J.C. Nie, Formation of two-dimensional Electron gas at Amorphous/crystalline oxide interfaces. Sci. Rep. 8, 404 (2018)Google Scholar
  53. 53.
    M. Basletic, J.-L. Maurice, C. Carretero, G. Herranz, O. Copie, M. Bibes, E. Jacquet, K. Bouzehouane, S. Fusil, A. Barthelemy, Mapping the spatial distribution of charge carriers in LaAlO3/SrTiO3 heterostructures. Nat. Mater. 7(8), 621–625 (2008)Google Scholar
  54. 54.
    O. Copie, V. Garcia, C. Boedefeld, C. Carretero, M. Bibes, G. Herranz, E. Jacquet, J.-L. Maurice, B. Vinter, S. Fusil, K. Bouzehouane, H. Jaffres, A. Barthelemy, Towards two-dimensional metallic behavior at LaAlO3/SrTiO3 interfaces. Phys. Rev. Lett. 102, 216804 (2009)Google Scholar
  55. 55.
    B.C. Huang, Y.-P. Chiu, P.C. Huang, W.C. Wang, V.T. Tra, J.C. Yang, Q. He, J.Y. Lin, C.S. Chang, Y.H. Chu, Mapping band alignment across complex oxide Heterointerfaces. Phys. Rev. Lett. 109(24), 246807 (2012)Google Scholar
  56. 56.
    M. Ben Shalom, C.W. Tai, Y. Lereah, M. Sachs, E. Levy, D. Rakhmilevitch, A. Palevski, Y. Dagan, Anisotropic magnetotransport at the SrTiO3/LaAlO3 interface. Phys. Rev. B 80, 140403 (2009)Google Scholar
  57. 57.
    H.X. Xue, C.J. Li, Y.P. Hong, X.X. Wang, Y.C. Li, K.J. Liu, W.M. Jiang, M.R. Liu, L. He, R.F. Dou, C.M. Xiong, J.C. Nie, Temperature dependence of the conductive layer thickness at the LaAlO3/SrTiO3 heterointerface. Phys. Rev. B 96, 235310 (2017)Google Scholar
  58. 58.
    D. Saint-James, P.G. Gennes, Onset of superconductivity in decreasing fields. Phys. Lett. 7, 306 (1963)Google Scholar
  59. 59.
    M. Strongin, O.F. Kammerer, D.G. Schweitzer, P.P. Craig, A. Paskin, Surface superconductivity in type 1+type 2 superconductors. Phys. Rev. Lett. 12, 442 (1964)Google Scholar
  60. 60.
    V.L. Ginzburg, On surface superconductivity. Phys. Lett. 13, 101 (1964)Google Scholar
  61. 61.
    M. Strongin, O.F. Kammerer, J.E. Crow, R.D. Parks, D.H. Douglass, M.A. Jensen, Enhanced superconductivity in layered metallic films. Phys. Rev. Lett. 21, 1320 (1968)Google Scholar
  62. 62.
    S. Gariglio, M. Gabay, J. Mannhart, J.-M. Triscone, Interface superconductivity. Physica C 514, 189–198 (2015)Google Scholar
  63. 63.
    G. Logvenov, A. Gozar, I. Bozovic, High-temperature superconductivity in a single copper-oxygen plane. Science 326, 699 (2009)Google Scholar
  64. 64.
    G. Binnig, A. Baratoff, H.E. Hoenig, J.G. Bednorz, 2-band superconductivity in Nb doped SrTiO3. Phys. Rev. Lett. 45(16), 1352 (1980)Google Scholar
  65. 65.
    V. Koerting, Q.S. Yuan, P.J. Hirschfeld, T. Kopp, J. Mannhart, Interface-mediated pairing in field effect devices. Phys. Rev. B 71(10), 104510 (2005)Google Scholar
  66. 66.
    N. Pavlenko, T. Kopp, Electrostatic interface tuning in correlated superconducting heterostructures. Phys. Rev. B 72(17), 174516 (2005)Google Scholar
  67. 67.
    V. Berezinskii, Destruction of long-range order in one-dimensional and 2-dimensional systems having a continuous symmetry group 1-classical systems. Sov. Phys. JETP 32, 493–500 (1971)MathSciNetGoogle Scholar
  68. 68.
    V. Berezinskii, Destruction of long-range order in one-dimensional and 2-dimensional systems possessing a continuous symmetry group.2. Quantum systems. Sov. Phys. JETP 34, 610 (1972)Google Scholar
  69. 69.
    J.M. Kosterlitz, D.J. Thouless, Long-range order and metastability in 2-dimensional solids and superfluids. J. Phys. C 5(11), L124 (1972)Google Scholar
  70. 70.
    J.M. Kosterlitz, D.J. Thouless, Ordering, metastability and phase-transitions in 2 dimensional systems. J. Phys. C 6(7), 1181 (1973)Google Scholar
  71. 71.
    J.V. José, 40 Years of Berezinskii-Kosterlitz-Thouless Theory[M]. (World Scientific, Singapore, 2013)zbMATHGoogle Scholar
  72. 72.
    M. Beasley, J.E. Mooij, T.P. Orlando, Possibility of vortex-antivortex pair dissociation in 2-dimensional superconductors. Phys. Rev. Lett. 42(17), 1165 (1979)Google Scholar
  73. 73.
    M. Gabay, A. Kapitulnik, Vortex-antivortex crystallization in thin superconducting and superfluid films. Phys. Rev. Lett. 71(13), 2138 (1993)Google Scholar
  74. 74.
    K. Medvedyeva, B.J. Kim, P. Minnhagen, Analysis of current-voltage characteristics of two-dimensional superconductors: Finite-size scaling behavior in the vicinity of the Kosterlitz-Thouless transition. Phys. Rev. B 62(21), 14531 (2000)Google Scholar
  75. 75.
    B.I. Halperin, D.R. Nelson, Resistive transition in superconducting films. J. Low Temp. Phys. 36(5–6), 599–616 (1979)Google Scholar
  76. 76.
    N. Reyren, S. Gariglio, A.D. Caviglia, D. Jaccard, T. Schneider, J.–.M. Triscone, Anisotropy of the superconducting transport properties of the LaAlO3/SrTiO3 interface. Appl. Phys. Lett. 94(11), 112506 (2009)Google Scholar
  77. 77.
    J. Biscaras, N. Bergeal, A. Kushwaha, T. Wolf, A. Rastogi, R.C. Budhani, J. Lesueur, Two-dimensional superconductivity at a Mott insulator/band insulator interface LaTiO3/SrTiO3. Nat. Commun. 1, 89 (2010)Google Scholar
  78. 78.
    J. Biscaras, N. Bergeal, S. Hurand, C. Grossetete, A. Rastogi, R.C. Budhani, D. LeBoeuf, C. Proust, J. Lesueur, Two-dimensional superconducting phase in LaTiO3/SrTiO3 Heterostructures induced by high-mobility carrier doping. Phys. Rev. Lett. 108(24), 247004 (2012)Google Scholar
  79. 79.
    D. Fuchs, R. Schaefer, A. Sleem, R. Schneider, R. Thelen, H. von Loehneysen, Two-dimensional superconductivity between SrTiO3 and amorphous Al2O3. Appl. Phys. Lett. 105(9), 092602 (2014)Google Scholar
  80. 80.
    C.H. Ahn, A. Bhattacharya, M. Di Ventra, J.N. Eckstein, C.D. Frisbie, M.E. Gershenson, A.M. Goldman, I.H. Inoue, J. Mannhart, A.J. Millis, A.F. Morpurgo, D. Natelson, J.M. Triscone, Electrostatic modification of novel materials. Rev. Mod. Phys. 78(4), 1185 (2006)Google Scholar
  81. 81.
    A.D. Caviglia, S. Gariglio, N. Reyren, D. Jaccard, T. Schneider, M. Gabay, S. Thiel, G. Hammerl, J. Mannhart, J.-M. Triscone, Electric field control of the LaAlO3/SrTiO3 interface ground state. Nature 456(7222), 624–627 (2008)Google Scholar
  82. 82.
    C. Richter, H. Boschker, W. Dietsche, E. Fillis-Tsirakis, R. Jany, F. Loder, L.F. Kourkoutis, D.A. Muller, J.R. Kirtley, C.W. Schneider, J. Mannhart, Interface superconductor with gap behaviour like a high-temperature superconductor. Nature 502(7472), 528–531 (2013)Google Scholar
  83. 83.
    S.C. Shen, B.B. Chen, H.X. Xue, G. Cao, C.J. Li, X.X. Wang, Y.P. Hong, G.P. Guo, R.F. Dou, C.M. Xiong, L. He, J.C. Nie, Gate dependence of upper critical field in superconducting (110) LaAlO3/SrTiO3 interface. Sci. Rep. 6, 28379 (2016)Google Scholar
  84. 84.
    G.E.D.K. Prawiroatmodjo, M. Leijnse, F. Trier, Y.Z. Chen, D.V. Christensen, M. von Soosten, N. Pryds, T.S. Jespersen, Transport and excitations in a negative-U quantum dot at the LaAlO3/SrTiO3 interface. Nat. Commun. 8, 395 (2017)Google Scholar
  85. 85.
    G. Singh, A. Jouan, L. Benfatto, F. Couedo, P. Kumar, A. Dogra, R.C. Budhani, S. Caprara, M. Grilli, E. Lesne, A. Barthelemy, M. Bibes, C. Feuillet-Palma, J. Lesueur, N. Bergeal, Competition between electron pairing and phase coherence in superconducting interfaces. Nat. Commun. 9, 407 (2018)Google Scholar
  86. 86.
    Z.Y. Chen, A.G. Swartz, H. Yoon, H. Inoue, T. Merz, D. Lu, Y.W. Xie, H.T. Yuan, Y. Hikita, S. Raghu, H.Y. Hwang, Carrier density and disorder tuned superconductor-metal transition in a two-dimensional electron system. Nat. Commun. 9, 4008 (2018)Google Scholar
  87. 87.
    A. Brinkman, M. Huijben, M. Van Zalk, J. Huijben, U. Zeitler, J.C. Maan, W.G. Van der Wiel, G. Rijnders, D.H.A. Blank, H. Hilgenkamp, Magnetic effects at the interface between non-magnetic oxides. Nat. Mater. 6(7), 493–496 (2007)Google Scholar
  88. 88.
    Z. Salman, O. Ofer, M. Radovic, H. Hao, M. Ben Shalom, K.H. Chow, Y. Dagan, M.D. Hossain, C.D.P. Levy, W.A. MacFarlane, G.M. Morris, L. Patthey, M.R. Pearson, H. Saadaoui, T. Schmitt, D. Wang, R.F. Kiefl, Nature of weak magnetism in SrTiO3/LaAlO3 multilayers. Phys. Rev. Lett. 109(25), 257207 (2012)Google Scholar
  89. 89.
    B. Kalisky, J.A. Bert, B.B. Klopfer, C. Bell, H. Sato, M. Hosoda, Y. Hikita, H.Y. Hwang, K.A. Moler, Critical thickness for ferromagnetism in LaAlO3/SrTiO3 heterostructures. Nat. Commun. 3, 922 (2012)Google Scholar
  90. 90.
    J.-S. Lee, Y.W. Xie, H.K. Sato, C. Bell, Y. Hikita, H.Y. Hwang, C.–.C. Kao, Titanium d(xy) ferromagnetism at the LaAlO3/SrTiO3 interface. Nat. Mater. 12(8), 703–706 (2013)Google Scholar
  91. 91.
    F. Bi, M.C. Huang, S. Ryu, H. Lee, C.W. Bark, C.B. Eom, P. Irvin, J. Levy, Room-temperature electronically-controlled ferromagnetism at the LaAlO3/SrTiO3 interface. Nat. Commun. 5, 5019 (2014)Google Scholar
  92. 92.
    D. Dikin, M. Mehta, C.W. Bark, C.M. Folkman, C.B. Eom, V. Chandrasekhar, Coexistence of superconductivity and ferromagnetism in two dimensions. Phys. Rev. Lett. 107(5), 056802 (2011)Google Scholar
  93. 93.
    Ariando, X. Wang, G. Baskaran, Z.Q. Liu, J. Huijben, J.B. Yi, A. Annadi, A.R. Barman, A. Rusydi, S. Dhar, Y.P. Feng, J. Ding, H. Hilgenkamp, T. Venkatesan, Electronic phase separation at the LaAlO3/SrTiO3 interface. Nat. Commun. 2, 188 (2011)Google Scholar
  94. 94.
    L. Li, C. Richter, J. Mannhart, R.C. Ashoori, Coexistence of magnetic order and two-dimensional superconductivity at LaAlO3/SrTiO3 interfaces. Nat. Phys. 7(10), 762–766 (2011)Google Scholar
  95. 95.
    J.A. Bert, B. Kalisky, C. Bell, M. Kim, Y. Hikita, H.Y. Hwang, K.A. Moler, Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface. Nat. Phys. 7(10), 767–771 (2011)Google Scholar
  96. 96.
    N. Pavlenko, T. Kopp, E.Y. Tsymbal, G.A. Sawatzky, J. Mannhart, Magnetic and superconducting phases at the LaAlO3/SrTiO3 interface: The role of interfacial Ti 3d electrons. Phys. Rev. B 85(2), 020407 (2012)Google Scholar
  97. 97.
    Shen S. C., Xing Y., Wang P. J., Liu H. W., Fu H. L., Zhang Y. W., He L., Xie X. C., Lin X., Nie J. C., and Wang J., Observation of quantum Griffiths singularity and ferromagnetism at superconducting LaAlO3/SrTiO3(110) Interface, Phys. Rev. B, 2016, 94: 144517Google Scholar
  98. 98.
    K. Michaeli, A.C. Potter, P.A. Lee, Superconducting and ferromagnetic phases in SrTiO3/LaAlO3 oxide Interface structures: Possibility of finite momentum pairing. Phys. Rev. Lett. 108, 117003 (2012)Google Scholar
  99. 99.
    P. Fulde, R.A. Ferrell, Superconductivity in strong spin-exchange field. Phys. Rev. 135(3A), A550 (1964)Google Scholar
  100. 100.
    A.I. Larkin, Y.N. Ovchinnikov, Inhomogeneous state of superconductors. Sov. Phys. JETP 20, 762–769 (1965)MathSciNetGoogle Scholar
  101. 101.
    M.S. Scheurer, J. Schmalian, Topological superconductivity and unconventional pairing in oxide interfaces. Nat. Commun. 6, 6005 (2015)Google Scholar
  102. 102.
    M.M. Mehta, D.A. Dikin, C.W. Bark, S. Ryu, C.M. Folkman, C.B. Eom, V. Chandrasekhar, Evidence for charge-vortex duality at the LaAlO3/SrTiO3 interface. Nat. Commun. 3, 955 (2012)Google Scholar
  103. 103.
    J.A. Bert, K.C. Nowack, B. Kalisky, H. Noad, J.R. Kirtley, C. Bell, H. Sato, M. Hosoda, Y. Hikita, H.Y. Hwang, K.A. Moler, Gate-tuned superfluid density at the superconducting LaAlO3/SrTiO3 interface. Phys. Rev. B 86(6), 060503 (2012)Google Scholar
  104. 104.
    L. Benfatto, C. Castellani, T. Giamarchi, Broadening of the Berezinskii-Kosterlitz-Thouless superconducting transition by inhomogeneity and finite-size effects. Phys. Rev. B 80(21), 214506 (2009)Google Scholar
  105. 105.
    S. Caprara, M. Grilli, L. Benfatto, C. Castellani, Effective medium theory for superconducting layers: A systematic analysis including space correlation effects. Phys. Rev. B 84(1), 014514 (2011)Google Scholar
  106. 106.
    S. Caprara, F. Peronaci, M. Grilli, Intrinsic instability of electronic interfaces with strong Rashba coupling. Phys. Rev. Lett. 109(19), 196401 (2012)Google Scholar
  107. 107.
    S. Caprara, J. Biscaras, N. Bergeal, D. Bucheli, S. Hurand, C. Feuillet-Palma, A. Rastogi, R.C. Budhani, J. Lesueur, M. Grilli, Multiband superconductivity and nanoscale inhomogeneity at oxide interfaces. Phys. Rev. B 88(2), 020504 (2013)Google Scholar
  108. 108.
    S. Banerjee, O. Erten, M. Randeria, Ferromagnetic exchange, spin-orbit coupling and spiral magnetism at the LaAlO3/SrTiO3 interface. Nat. Phys. 9(10), 626–630 (2013)Google Scholar
  109. 109.
    Y. Maeno, H. Hashimoto, K. Yoshida, S. Nishizaki, T. Fujita, J.G. Bednorz, F. Lichtenberg, Superconductivity in a layered perovskite without copper. Nature 372, 532 (1994)Google Scholar
  110. 110.
    Y. Maeno, S. Nishizaki, K. Yoshida, S. Ikeda, T. Fujita, Normal-state and superconducting properties of Sr2RuO4. J. Low Temp. Phys. 105, 1577 (1996)Google Scholar
  111. 111.
    K. Ishida, Y. Kitaoka, K. Asayama, S. Ikeda, S. Nishizaki, Y. Maeno, K. Yoshida, T. Fujita, Anisotropic pairing in superconducting Sr2RuO4: Ru NMR and NQR studies. Phys. Rev. B 56, R505 (1997)Google Scholar
  112. 112.
    A.P. Mackenzie, R.K.W. Haselwimmer, A.W. Tyler, G.G. Lonzarich, Y. Mori, S. Nishizaki, Y. Maeno, Extremely strong dependence of superconductivity on disorder in Sr2RuO4. Phys. Rev. Lett. 80, 161 (1998)Google Scholar
  113. 113.
    K. Yada, S. Onari, Y. Tanaka, J. Inoue, Electrically controlled superconducting states at the heterointerface SrTiO3/LaAlO3. Phys. Rev. B 80, 140509 (2009)Google Scholar
  114. 114.
    V. Kozii, L. Fu, Odd-parity superconductivity in the vicinity of inversion symmetry breaking in spin-orbit-coupled systems. Phys. Rev. Lett. 115, 207002 (2015)Google Scholar
  115. 115.
    S. Nakosai, Y. Tanaka, N. Nagaosa, Topological superconductivity in bilayer Rashba system. Phys. Rev. Lett. 108, 147003 (2012)Google Scholar
  116. 116.
    D. Stornaiuolo, D. Massarotti, R. Di Capua, P. Lucignano, G.P. Pepe, M. Salluzzo, F. Tafuri, Signatures of unconventional superconductivity in the LaAlO3/SrTiO3 two-dimensional system. Phys. Rev. B 95, 140502R (2017)Google Scholar
  117. 117.
    D.A. Wollman, D.J. Vanharlingen, J. Giapintzakis, D.M. Ginsberg, Evidence for d(x2-y2) pairing from the magnetic-field modulation of YBa2Cu3O7-δ Josephson-junctions. Phys. Rev. Lett. 74, 797 (1995)Google Scholar
  118. 118.
    R. Jin, Y. Zadorozhny, Y. Liu, D.G. Schlom, Y. Mori, Y. Maeno, Phys. Rev. B 59, 4433 (1999)Google Scholar
  119. 119.
    C.C. Tsuei, J.R. Kirtley, Pairing symmetry in cuprate superconductors. Rev. Mod. Phys. 72, 969 (2000)Google Scholar
  120. 120.
    R. Jin, Y. Liu, Z.Q. Mao, Y. Maeno, Experimental observation of the selection rule in Josephson coupling between in and Sr2RuO4. Europhys. Lett. 51, 341 (2000)Google Scholar
  121. 121.
    I. Bonalde, B.D. Yanoff, M.B. Salamon, D.J. Van Harlingen, E.M.E. Chia, Z.Q. Mao, Y. Maeno, Temperature dependence of the penetration depth in Sr2RuO4: Evidence for nodes in the gap function. Phys. Rev. Lett. 85, 4775 (2000)Google Scholar
  122. 122.
    A. Sumiyama, T. Endo, Y. Oda, Y. Yoshida, A. Mukai, A. Ono, Y. Onuki, The Josephson effect in contacts between the spin-triplet superconductor Sr2RuO4 and conventional superconductors. Physica C 367, 129 (2002)Google Scholar
  123. 123.
    S.K. Yip, O.F.D. Bonfim, P. Kumar, Supercurrent tunneling between conventional and unconventional superconductors-a Ginzburg-Landau approach. Phys. Rev. B 41, 11214 (1990)Google Scholar
  124. 124.
    Y. Liu, K.D. Nelson, Z.Q. Mao, R. Jin, Y. Maeno, Tunneling and phase-sensitive studies of the pairing symmetry in Sr2RuO4. J. Low Temp. Phys. 131, 1059 (2003)Google Scholar
  125. 125.
    C.W. Hicks, D.O. Brodsky, E.A. Yelland, A.S. Gibbs, J.A.N. Bruin, M.E. Barber, S.D. Edkins, K. Nishimura, S. Yonezawa, Y. Maeno, A.P. Mackenzie, Strong increase of T-c of Sr2RuO4 under both tensile and compressive strain. Science 344, 283 (2014)Google Scholar
  126. 126.
    S. Sachdev, Quantum phase transitions[M] (Cambridge University Press, Cambridge, 2011)zbMATHGoogle Scholar
  127. 127.
    S.L. Sondhi, S.M. Girvin, J.P. Carini, D. Shahar, Continuous quantum phase transitions. Rev. Mod. Phys. 69(1), 315 (1997)Google Scholar
  128. 128.
    L. Carr, Understanding Quantum Phase Transitions[M]. City (CRC, 2010)Google Scholar
  129. 129.
    J.S. Parker, D.E. Read, A. Kumar, P. Xiong, Superconducting quantum phase transitions tuned by magnetic impurity and magnetic field in ultrathin a-Pb films. Europhys. Lett. 75(6), 950 (2006)Google Scholar
  130. 130.
    A.F. Hebard, M.A. Paalanen, Magnetic-field-tuned superconductor-insulator transition in 2-dimensional films. Phys. Rev. Lett. 65(7), 927 (1990)Google Scholar
  131. 131.
    G. Sambandamurthy, L.W. Engel, A. Johansson, D. Shahar, Superconductivity-related insulating behavior. Phys. Rev. Lett. 92(10), 107005 (2004)Google Scholar
  132. 132.
    T.I. Baturina, J. Bentner, C. Strunk, M.R. Baklanov, A. Satta, From quantum corrections to magnetic-field-tuned superconductor-insulator quantum phase transition in TIN films. Physica B 359, 500–502 (2005)Google Scholar
  133. 133.
    M. Strongin, R.S. Thompson, O.F. Kammerer, J.E. Crow, Destruction of superconductivity in disordered near-monolayer films. Phys. Rev. B 1(3), 1078 (1970)Google Scholar
  134. 134.
    R.C. Dynes, J.P. Garno, J.M. Rowell, 2-dimensional electrical-conductivity in quench-condensed metal-films. Phys. Rev. Lett. 40(7), 479 (1978)Google Scholar
  135. 135.
    S. Oh, T.A. Crane, D.J. Van Harlingen, J.N. Eckstein, Doping controlled superconductor-insulator transition in Bi2Sr2-xLaxCaCu2O8+δ. Phys. Rev. Lett. 96(10), 107003 (2006)Google Scholar
  136. 136.
    K. Semba, A. Matsuda, Superconductor-to-insulator transition and transport properties of underdoped YBa2Cu3Oy crystals. Phys. Rev. Lett. 86(3), 496 (2001)Google Scholar
  137. 137.
    K.A. Parendo, K.H. Sarwa, B. Tan, A. Bhattacharya, M. Eblen-Zayas, N.E. Staley, A.M. Goldman, Electrostatic tuning of the superconductor-insulator transition in two dimensions. Phys. Rev. Lett. 94(19), 197004 (2005)Google Scholar
  138. 138.
    A. Goldman, Superconductor-insulator transitions. Int. J. Mod. Phys. B 24(20–21), 4081–4101 (2010)zbMATHGoogle Scholar
  139. 139.
    V.F. Gantmakher, V.T. Dolgopolov, Superconductor-insulator quantum phase transition. Physics-Uspekhi 53(1), 1–49 (2010)Google Scholar
  140. 140.
    Y.-H. Lin, J. Nelson, A.M. Goldman, Superconductivity of very thin films: The superconductor-insulator transition. Physica C 514, 130–141 (2015)Google Scholar
  141. 141.
    S. Maekawa, H. Fukuyama, Localization effects in two-dimensional superconductors. J. Phys. Soc. Jpn. 51(5), 1380–1385 (1982)Google Scholar
  142. 142.
    H. Ebisawa, H. Fukuyama, S. Maekawa, Superconducting transition-temperature of dirty thin films in weakly localized regime. J. Phys. Soc. Jpn. 54(6), 2257–2268 (1985)Google Scholar
  143. 143.
    A.M. Finkelshtein, Superconducting transition-temperature in amorphous films. JETP Lett. 45(1), 46–49 (1987)Google Scholar
  144. 144.
    M.P.A. Fisher, Quantum phase-transitions in disordered 2-dimensional superconductors. Phys. Rev. Lett. 65(7), 923 (1990)MathSciNetGoogle Scholar
  145. 145.
    M.P.A. Fisher, G. Grinstein, S.M. Girvin, Presence of quantum diffusion in two dimensions: Universal resistance at the superconductor-insulator transition. Phys. Rev. Lett. 64(5), 587 (1990)Google Scholar
  146. 146.
    M.-C. Cha, M.P.A. Fisher, S.M. Girvin, M. Wallin, A.P. Young, Universal conductivity of 2-dimensional films at the superconductor-insulator transition. Phys. Rev. B 44(13), 6883 (1991)Google Scholar
  147. 147.
    D.B. Haviland, Y. Liu, A.M. Goldman, Onset of superconductivity in the two-dimensional limit. Phys. Rev. Lett. 62(18), 2180 (1989)Google Scholar
  148. 148.
    A. Larkin, Superconductor-insulator transitions in films and bulk materials. Ann. Phys. 8(7–9), 785–794 (1999)zbMATHGoogle Scholar
  149. 149.
    Y.M. Strelniker, A. Frydman, S. Havlin, Percolation model for the superconductor-insulator transition in granular films. Phys. Rev. B 76(22), 224528 (2007)Google Scholar
  150. 150.
    J. Biscaras, N. Bergeal, S. Hurand, C. Feuillet-Palma, A. Rastogi, R.C. Budhani, M. Grilli, S. Caprara, J. Lesueur, Multiple quantum criticality in a two-dimensional superconductor. Nat. Mater. 12(6), 542–548 (2013)Google Scholar
  151. 151.
    Y. Xing, H.M. Zhang, H.L. Fu, H.W. Liu, Y. Sun, J.P. Peng, F. Wang, X. Lin, X.C. Ma, Q.K. Xue, J. Wang, X.C. Xie, Quantum Griffiths singularity of superconductor - metal transition in Ga thin films. Science 350, 542 (2015)MathSciNetzbMATHGoogle Scholar
  152. 152.
    X.Y. Shi, P.V. Lin, T. Sasagawa, V. Dobrosavljević, D. Popović, Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La2-xSrxCuO4. Nat. Phys. 10(6), 437–443 (2014)Google Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Department of PhysicsBeijing Normal UniversityBeijingPeople’s Republic of China

Personalised recommendations