Table of Contents
Physics Research International
Volume 2014, Article ID 454939, 7 pages
http://dx.doi.org/10.1155/2014/454939
Research Article

Multigap Superconductivity in the Ferromagnetic Superconductor UCoGe Revealed by Thermal Conductivity Measurements

1Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
2Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, Switzerland
3Institut Nanosciences et Cryogénie, Commissariat à l’Énergie Atomique et aux Énergies Alternatives, 38054 Grenoble, France
4University Joseph Fourier, 38041 Grenoble, France
5Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313, Japan

Received 7 July 2014; Revised 15 September 2014; Accepted 17 September 2014; Published 9 October 2014

Academic Editor: Zhiqiang Mao

Copyright © 2014 Ludovic Howald et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Linked References

  1. N. T. Huy, A. Gasparini, D. E. de Nijs et al., “Superconductivity on the border of weak itinerant ferromagnetism in UCoGe,” Physical Review Letters, vol. 99, no. 6, Article ID 067006, 4 pages, 2007. View at Publisher · View at Google Scholar · View at Scopus
  2. N. T. Huy, D. E. de Nijs, Y. K. Huang, and A. de Visser, “Unusual upper critical field of the ferromagnetic superconductor UCoGe,” Physical Review Letters, vol. 100, no. 7, Article ID 077002, 2008. View at Publisher · View at Google Scholar · View at Scopus
  3. A. de Visser, N. T. Huy, A. Gasparini et al., “Muon spin rotation and relaxation in the superconducting ferromagnet UCoGe,” Physical Review Letters, vol. 102, no. 16, Article ID 167003, 2009. View at Publisher · View at Google Scholar · View at Scopus
  4. T. Ohta, T. Hattori, K. Ishida et al., “Microscopic coexistence of ferromagnetism and superconductivity in single-crystal UCoGe,” Journal of the Physical Society of Japan, vol. 79, no. 2, Article ID 023707, 5 pages, 2010. View at Publisher · View at Google Scholar
  5. T. Ohta, Y. Nakai, Y. Ihara et al., “Ferromagnetic quantum critical fluctuations and anomalous coexistence of ferromagnetism and superconductivity in UCoGe revealed by Co-NMR and NQR studies,” Journal of the Physical Society of Japan, vol. 77, Article ID 023707, 5 pages, 2008. View at Publisher · View at Google Scholar · View at Scopus
  6. D. Aoki, T. D. Matsuda, V. Taufour, E. Hassinger, G. Knebel, and J. Flouquet, “Extremely large and anisotropic upper critical field and the ferromagnetic instability in UCoGe,” Journal of the Physical Society of Japan, vol. 78, no. 11, Article ID 113709, 4 pages, 2009. View at Publisher · View at Google Scholar
  7. V. P. Mineev, “Paramagnetic limit in ferromagnetic superconductors with triplet pairing,” Physical Review B, vol. 81, Article ID 180504, 4 pages, 2010. View at Publisher · View at Google Scholar
  8. G. Binnig, A. Baratoff, H. E. Hoenig, and J. G. Bednorz, “Two-band superconductivity in Nb-doped SrTiO3,” Physical Review Letters, vol. 45, no. 16, pp. 1352–1355, 1980. View at Publisher · View at Google Scholar · View at Scopus
  9. F. Bouquet, Y. Wang, I. Sheikin et al., “Specific heat of single crystal MgB2: a two-band superconductor with two different anisotropies,” Physical Review Letters, vol. 89, Article ID 257001, 2002. View at Publisher · View at Google Scholar · View at Scopus
  10. G. Seyfarth, J. P. Brison, M.-A. Méasson et al., “Multiband superconductivity in the heavy fermion compound PrOs4Sb12,” Physical Review Letters, vol. 95, no. 10, Article ID 107004, 2005. View at Publisher · View at Google Scholar · View at Scopus
  11. G. Seyfarth, J. P. Brison, G. Knebel, D. Aoki, G. Lapertot, and J. Flouquet, “Multigap superconductivity in the heavy-fermion system CeCoIn5,” Physical Review Letters, vol. 101, no. 4, Article ID 046401, 2008. View at Publisher · View at Google Scholar · View at Scopus
  12. R. Khasanov, A. Shengelaya, A. Maisuradze et al., “Experimental evidence for two gaps in the high-temperature La1.83Sr0.17CuO4 superconductor,” Physical Review Letters, vol. 98, no. 5, Article ID 057007, 2007. View at Publisher · View at Google Scholar · View at Scopus
  13. J. Yang and G. Q. Zheng, “Multiple superconducting gaps, anisotropic spin fluctuations and spin-orbit coupling in iron-pnictides,” Modern Physics Letters B, vol. 26, no. 15, Article ID 1230008, 20 pages, 2012. View at Publisher · View at Google Scholar · View at Scopus
  14. M. Samsel-Czekała, S. Elgazzar, P. M. Oppeneer, E. Talik, W. Walerczyk, and R. Troć, “The electronic structure of UCoGe by ab initio calculations and XPS experiment,” Journal of Physics Condensed Matter, vol. 22, no. 1, Article ID 015503, 2010. View at Publisher · View at Google Scholar · View at Scopus
  15. V. P. Mineev and T. Champel, “Theory of superconductivity in ferromagnetic superconductors with triplet pairing,” Physical Review B: Condensed Matter and Materials Physics, vol. 69, no. 14, Article ID 144521, 2004. View at Publisher · View at Google Scholar · View at Scopus
  16. F. Hardy and A. D. Huxley, “P-Wave superconductivity in the ferromagnetic superconductor URhGe,” Physical Review Letters, vol. 94, no. 24, Article ID 247006, 2005. View at Publisher · View at Google Scholar · View at Scopus
  17. D. Aoki, T. D. Matsuda, F. Hardy et al., “Superconductivity reinforced by magnetic field and the magnetic instability in uranium ferromagnets,” Journal of the Physical Society of Japan, vol. 80, supplement A, Article ID SA008, 6 pages, 2011. View at Publisher · View at Google Scholar
  18. L. Howald, Interactions between superconductivity and quantum criticality in CeCoIn5, URhGe and UCoGe [Ph.D. thesis], Université de Grenoble, 2011, http://tel.archives-ouvertes.fr/tel-00584598.
  19. J. Lowell and J. B. Sousa, “Mixed-state thermal conductivity of type II superconductors,” Journal of Low Temperature Physics, vol. 3, no. 1, pp. 65–87, 1970. View at Publisher · View at Google Scholar
  20. E. Boaknin, M. A. Tanatar, J. Paglione et al., “Heat conduction in the vortex state of NbSe2: evidence for multiband superconductivity,” Physical Review Letters, vol. 90, no. 11, Article ID 117003, 2003. View at Google Scholar · View at Scopus
  21. A. V. Sologubenko, J. Jun, S. M. Kazakov, J. Karpinski, and H. R. Ott, “Thermal conductivity of single-crystalline MgB2,” Physical Review B: Condensed Matter and Materials Physics, vol. 66, no. 1, Article ID 014504, 2002. View at Publisher · View at Google Scholar · View at Scopus
  22. C. Proust, E. Boaknin, R. W. Hill, L. Taillefer, and A. P. Mackenzie, “Heat transport in a strongly overdoped cuprate: Fermi liquid and a pure d-wave BCS superconductor,” Physical Review Letters, vol. 89, no. 14, Article ID 147003, 2002. View at Google Scholar · View at Scopus
  23. H. Suderow, J. P. Brison, J. Flouquet, A. W. Tyler, and Y. Maeno, “Very low temperature thermal conductivity in the layered perovskite superconductor Sr2RuO4,” Journal of Physics Condensed Matter, vol. 10, no. 34, pp. L597–L602, 1998. View at Publisher · View at Google Scholar · View at Scopus
  24. M. Suzuki, M. A. Tanatar, N. Kikugawa, Z. O. Mao, Y. Maeno, and T. Ishiguro, “Universal heat transport in Sr2RuO4,” Physical Review Letters, vol. 88, Article ID 227004, 2002. View at Google Scholar · View at Scopus
  25. M. J. Graf, S.-K. Yip, J. A. Sauls, and D. Rainer, “Electronic thermal conductivity and the Wiedemann-Franz law for unconventional superconductors,” Physical Review B—Condensed Matter and Materials Physics, vol. 53, no. 22, pp. 15147–15161, 1996. View at Publisher · View at Google Scholar · View at Scopus
  26. M. Taupin, L. Howald, D. Aoki, J. Flouquet, and J. P. Brison, “Existence of anisotropic spin fluctuations at low temperature in the normal phase of the superconducting ferromagnet UCoGe,” Physical Review B, vol. 89, Article ID 041108, 2014. View at Publisher · View at Google Scholar
  27. D. Aoki, M. Taupin, C. Paulsen et al., “Field-induced phenomena in ferromagnetic superconductors UCoGe and URhGe,” Journal of the Physical Society of Japan, vol. 81, Article ID SB002, 6 pages, 2012. View at Publisher · View at Google Scholar · View at Scopus
  28. J. M. Ziman, Principles of the Theory of Solids, Cambridge University Press, London, UK, 2nd edition, 1979. View at MathSciNet
  29. K. Prokeš, A. de Visser, Y. K. Huang, B. Fåk, and E. Ressouche, “Anomalous spin distribution in the superconducting ferromagnet UCoGe studied by polarized neutron diffraction,” Physical Review B, vol. 81, Article ID 180407, 2010. View at Publisher · View at Google Scholar · View at Scopus
  30. Y. Matsuda, K. Izawa, and I. Vekhter, “Nodal structure of unconventional superconductors probed by angle resolved thermal transport measurements,” Journal of Physics: Condensed Matter, vol. 18, no. 44, pp. R705–R752, 2006. View at Publisher · View at Google Scholar · View at Scopus
  31. L. Malone, L. Howald, A. Pourret et al., “Thermoelectricity of the ferromagnetic superconductor UCoGe,” Physical Review B—Condensed Matter and Materials Physics, vol. 85, no. 2, Article ID 024526, 2012. View at Publisher · View at Google Scholar · View at Scopus