Author

Abstract

To understand the mechanism of superconductivity in unconventional super onductors is one of the big challenges in the field of superconductivity. Based on the BCS theory, there is a direct relation between the pairing mechanism and the symmetry of the order parameter. Therefore, identification of the structure of the superconducting gap or the order parameter provides key information on the pairing mechanism. The s-wave conventional superconductors have full point symmetry of the crystal lattice, thus they have full gap symmetry around the Fermi surface. This leads to the exponential temperature dependence of many physical properties in the superconducting state at low temperature. However, the presence of nodes imposed by symmetry in the gap function of unconventional superconductors implies a different order parameter other than conventional s-wave, which may lead to a different pairing mechanism. Here, we show how thermal conductivity measurements in CeIrIn5 at very low temperatures detect the superconducting gap structure.

Keywords

1. N D Mathur, F Grosche, G Lonzarich et al., Nature 394 (1998) 39.
2. L Taillefer, Annu. Rev. Condens. Matt. Phys. 1 (2010) 51
3. P G Pagliuso et al., Physica B 312-313 (2002) 129.
4. J-Ph Reid, A Juneau-Fecteau, R T Gordon, S R de Cotret, N Doiron-Leyraud, X G Luo, H Shakeripour et al., Supercond. Sci. Technol. 25 (2012) 084013.
5. J Annett, “Superconductivity, Superfluity and Condensation”, Oxford University Press (2005).
6. M J Graf, Phys. Rev. B 53 (1996) 15147.
7. M R Norman and P J Hirschfeld, Phys. Rev. B 53 (1996) 5706.
8. V P Mineev and K V Samokhin, “Introduction to Unconventional Superconductivity”, London: Gordon and Breach (1999).
9. N Ashcroft and N Mermin, “Solid State Physics”, W.B. Saunders Company (1976).
10. R Joynt and L Taillefer, Rev. Mod. Phys. 74, 1 (2002) 235.
11. C Petrovic, P Pagliuso, et al., J. Phys: Condens. Matter 13 (2001) L337.
12. C Petrovic, R Movshovic et al., Europhys. Lett. 53 (2001) 354.
13. M A Tanatar et al., Phys. Rev. Lett. 95, 6 (2005) 067002.
14. H Shakeripour et al., Phys. Rev. Lett. 99 (2007) 187004.
15. K Izawa et al., Phys. Rev. Lett. 87, 5 (2001) 057002.
16. H Aoki et al., J. Phys: Condensed Matter 16 (2004) L13.
17. T Maehira, T Hotta, K Ueda, and A Hasegawa, J. Phys. Soc. Jpn. 72 (2003) 854.
18. Y Haga et al., Phys. Rev. B 63 (2001) 060503.
19. H Shakeripour, C Petrovic, and L Taillefer, New J. Phys. 11 (2009) 055065.
20. H Shakeripour, M A Tanatar, C Petrovic, and L Taillefer, Phys. Rev. B 82 (2010) 184531.
21. C Tsuei and J Kirtley, Rev. Mod. Phys. 72, 4 (2000) 969.

ارتقاء امنیت وب با وف ایرانی