Abstract
We study a two band superconducting, assuming that we have two tight binding bands, {epsilon}{sub 2}(k-vector) = {epsilon}{sub 2}{sup (0)} - t{sub 2}[cos(k{sub x}) + cos(k{sub y}) + s{sub 2} cos(k{sub z})] - {mu} and {epsilon}{sub 3}(k-vector) {epsilon}{sub 3}{sup (0)} - t{sub 3} [cos(k{sub x}) + cos(k{sub y})+s{sub 3} cos(k{sub z})] - {mu}. We solve the two gap equations at T = T{sub c} and calculate T{sub c} x n and {mu} x n for various values of pairing interaction, V, and Debye frequency, {omega}{sub D}. Also, from an expression developed in a previous paper by two of the present authors, we calculate {alpha} x n, where n is the number of carriers per site per band and {alpha} is the isotope exponent. We take only interband scattering, V, as a first approach. We find that in order to have superconductivity (T{sub c} {ne} 0), large values of V are necessary. Also, for V/{omega}{sub D} > 1, we obtain {alpha} > 1.00 and for V/{omega}{sub D}>1.00, the isotope exponent becomes less than 1. (author)
Rodriguez-Nunez, J J;
[1]
Schmidt, A A;
[2]
Bianconi, A;
[3]
Perali, A
[4]
- Lab. SUPERCOMP, Departamento de Fisica - FACYT - UC, Valencia (Venezuela) and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)
- Departamento de Matematica, UFSM, Santa Maria, RS (Brazil)
- Physics Department, Universita di Roma, Rome (Italy)
- Physics Department, University of Camerino, Camerino - MC (Italy)
Citation Formats
Rodriguez-Nunez, J J, Schmidt, A A, Bianconi, A, and Perali, A.
Two band superconductivity for MgB{sub 2}: T{sub c} and isotope exponent {alpha} as a function of the carrier number n and the role of the center of the band.
IAEA: N. p.,
2005.
Web.
Rodriguez-Nunez, J J, Schmidt, A A, Bianconi, A, & Perali, A.
Two band superconductivity for MgB{sub 2}: T{sub c} and isotope exponent {alpha} as a function of the carrier number n and the role of the center of the band.
IAEA.
Rodriguez-Nunez, J J, Schmidt, A A, Bianconi, A, and Perali, A.
2005.
"Two band superconductivity for MgB{sub 2}: T{sub c} and isotope exponent {alpha} as a function of the carrier number n and the role of the center of the band."
IAEA.
@misc{etde_20815686,
title = {Two band superconductivity for MgB{sub 2}: T{sub c} and isotope exponent {alpha} as a function of the carrier number n and the role of the center of the band}
author = {Rodriguez-Nunez, J J, Schmidt, A A, Bianconi, A, and Perali, A}
abstractNote = {We study a two band superconducting, assuming that we have two tight binding bands, {epsilon}{sub 2}(k-vector) = {epsilon}{sub 2}{sup (0)} - t{sub 2}[cos(k{sub x}) + cos(k{sub y}) + s{sub 2} cos(k{sub z})] - {mu} and {epsilon}{sub 3}(k-vector) {epsilon}{sub 3}{sup (0)} - t{sub 3} [cos(k{sub x}) + cos(k{sub y})+s{sub 3} cos(k{sub z})] - {mu}. We solve the two gap equations at T = T{sub c} and calculate T{sub c} x n and {mu} x n for various values of pairing interaction, V, and Debye frequency, {omega}{sub D}. Also, from an expression developed in a previous paper by two of the present authors, we calculate {alpha} x n, where n is the number of carriers per site per band and {alpha} is the isotope exponent. We take only interband scattering, V, as a first approach. We find that in order to have superconductivity (T{sub c} {ne} 0), large values of V are necessary. Also, for V/{omega}{sub D} > 1, we obtain {alpha} > 1.00 and for V/{omega}{sub D}>1.00, the isotope exponent becomes less than 1. (author)}
place = {IAEA}
year = {2005}
month = {Aug}
}
title = {Two band superconductivity for MgB{sub 2}: T{sub c} and isotope exponent {alpha} as a function of the carrier number n and the role of the center of the band}
author = {Rodriguez-Nunez, J J, Schmidt, A A, Bianconi, A, and Perali, A}
abstractNote = {We study a two band superconducting, assuming that we have two tight binding bands, {epsilon}{sub 2}(k-vector) = {epsilon}{sub 2}{sup (0)} - t{sub 2}[cos(k{sub x}) + cos(k{sub y}) + s{sub 2} cos(k{sub z})] - {mu} and {epsilon}{sub 3}(k-vector) {epsilon}{sub 3}{sup (0)} - t{sub 3} [cos(k{sub x}) + cos(k{sub y})+s{sub 3} cos(k{sub z})] - {mu}. We solve the two gap equations at T = T{sub c} and calculate T{sub c} x n and {mu} x n for various values of pairing interaction, V, and Debye frequency, {omega}{sub D}. Also, from an expression developed in a previous paper by two of the present authors, we calculate {alpha} x n, where n is the number of carriers per site per band and {alpha} is the isotope exponent. We take only interband scattering, V, as a first approach. We find that in order to have superconductivity (T{sub c} {ne} 0), large values of V are necessary. Also, for V/{omega}{sub D} > 1, we obtain {alpha} > 1.00 and for V/{omega}{sub D}>1.00, the isotope exponent becomes less than 1. (author)}
place = {IAEA}
year = {2005}
month = {Aug}
}