Abstract
A detailed theoretical analysis of the experimental data obtained earlier in the studies of the tunneling spectra in the MgB2 two-band superconducting system has been performed. It is shown that most these data are well described in the generalized two-band Bardeen-Cooper-Schrieffer theory with the constants of the intraband electron-phonon interaction that reasonably coincide with the ab initio calculation results. It is shown that the existence of specific collective excitation in this system induced by oscillations of the relative phase of two superconducting condensates (the Leggett mode) indicates the overestimation of the constants of the interband electron-phonon interaction in the ab initio calculations. The dependences of the superconducting gaps and the Leggett mode frequency on the temperature and the disorder degree in the Mg1 − x Al x B2 system have been thoroughly studied.
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References
A. A. Golubov, J. Kortus, O. V. Dolgov, et al., J. Phys.: Condens. Matter. 14, 1353 (2002).
H. J. Choi, D. Roundy, H. Sun, et al., Phys. Rev. B 66, 020513 (2002).
Ya. G. Ponomarev, S. A. Kuzmichev, M. G. Mikheeva, et al., Solid State Commun. 129, 85 (2004).
Ya. G. Ponomarev, S. A. Kuzmichev, N. M. Kadomtseva, et al., Pis’ma Zh. Eksp. Teor. Fiz. 79, 597 (2004) [JETP Lett. 79, 484 (2004)].
M. Putti, C. Ferdegrini, M. Monni, et al., Phys. Rev. B 71, 144505 (2005).
P. Szabo, P. Samuely, Z. Pubalova, et al., Phys. Rev. B 75, 144507 (2007).
D. Daghero, D. Delaude, A. Galzolani, et al., J. Phys.: Condens. Matter. 20, 085225 (2008).
A. J. Leggett, Prog. Theor. Phys. 36, 901 (1966).
S. G. Sharapov, V. P. Gusynin, and H. Beck, Eur. Phys. J. B 30, 45 (2002).
Ya. G. Ponomarev, S. A. Kuzmichev, M. G. Mikheev, et al., Pis’ma Zh. Eksp. Teor. Fiz. 85, 52 (2007) [JETP Lett. 85, 46 (2007)].
Ya. G. Ponomarev, E. B. Tsokur, M. V. Sudakova, et al., Solid State Comm. 111, 513 (1999).
E. G. Maksimov, P. I. Arseev, and N. S. Maslova, Solid State Comm. 111, 391 (1999).
Ya. G. Ponomarev and E. G. Maksimov, Pis’ma Zh. Eksp. Teor. Fiz. 76, 455 (2002) [JETP Lett. 76, 394 (2002)].
K. Schlenga, R. Kleiner, G. Hehtfischer, et al., Phys. Rev. B 57, 14518 (1998).
A. Y. Liu, I. I. Mazin, and J. Kortus, Phys. Rev. Lett. 87, 087005 (2001).
P. B. Allen and B. Mitrovic, Solid State Phys. 37, 1 (1982).
O. V. Dolgov, R. K. Kremer, J. Kortus, et al., Phys. Rev. B 72, 024504 (2005).
B. Mitrovic, J. Phys.: Cond. Matter 16, 9013 (2004).
V. G. Kogan, C. Martin, and R. Prozorov, Phys. Rev. B 80, 014507 (2009).
I. I. Mazin and V. P. Antropov, Physica C 385, 49 (2003).
J. A. Liu, I. I. Mazin, and J. Kortus, Phys. Rev. Lett. 87, 087005 (2001).
J. Kortus, O. V. Dolgov, R. K. Kremer, et al., Phys. Rev. Lett. 94, 027002 (2005).
G. A. Ummarino, R. S. Gonnelli, S. Massida, and A. Bianconi, Physica C 407, 121 (2004).
J. Karpinski, N. D. Zhigadlo, G. Schuck, et al., Phys. Rev. B 71, 174506 (2006).
T. Klein, L. Lyard, J. Marcus, et al., Phys. Rev. B 73, 224528 (2006).
P. Szabo, P. Samuely, Z. Pribulova, et al., Phys. Rev. B 75, 144507 (2007).
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Original Russian Text © A.E. Karakozov, E.G. Maksimov, Ya.G. Ponomarev, 2010, published in Pis’ma v Zhurnal Éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2010, Vol. 91, No. 1, pp. 26–31.
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Karakozov, A.E., Maksimov, E.G. & Ponomarev, Y.G. Theoretical analysis of tunneling experiments in the MgB2 system. Jetp Lett. 91, 24–29 (2010). https://doi.org/10.1134/S0021364010010066
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DOI: https://doi.org/10.1134/S0021364010010066