PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y

Dahm T, TEWORDT L (1995)
Physica C Superconductivity 246(1-2): 61-72.

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Zeitschriftenaufsatz | Veröffentlicht | Englisch
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Abstract / Bemerkung
We have extended the previous fluctuation exchange approximation for the two-dimensional Hubbard model to a Fermi surface geometry approximating that of the YBa2Cu3O7-y cuprates. In spite of the poor nesting of this Fermi surface we obtain a broad commensurate peak in the spectral density of the dynamic spin susceptibility, Im chi(S)(q, omega), provided that the coupling is sufficiently large (U/t >/similar to 7). The antiparamagnons soften and the quasiparticles exhibit marginal Fermi liquid behavior as the band filling n tends to half filling n = 1. The eigenvalue lambda(d) for d(x2-y2) pairing increases with U and n, or decreasing T; however, we have not reached the pairing instability where lambda(d) = 1 (for example, lambda(d) = 0.91 for U/t = 6.8, n = 0.95, and T = 0.0224t). In the second part we use a coupling J(q) which is peaked at Q. Then we obtain a commensurate peak and d(x2-y2) wave superconductivity, for example, at U/t = 3.7, n = 0.85, and T-c = 0.039t. Below T-c, a gap and a peak at higher frequency develop rapidly in Im chi(s)(Q, omega), in qualitative agreement with neutron-scattering data. The density of stares N(omega) is linear in omega which is consistent with the observed low-temperature variation of the penetration depth. In the photoemission intensity along the antinode of the gap the quasiparticle peak shifts to lower frequency and a dip develops as T decreases below T-c. This behavior is in qualitative agreement with ARPES data obtained on Bi-2212.
Erscheinungsjahr
Zeitschriftentitel
Physica C Superconductivity
Band
246
Zeitschriftennummer
1-2
Seite
61-72
ISSN
PUB-ID

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Dahm T, TEWORDT L. PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y. Physica C Superconductivity. 1995;246(1-2):61-72.
Dahm, T., & TEWORDT, L. (1995). PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y. Physica C Superconductivity, 246(1-2), 61-72. doi:10.1016/0921-4534(95)00139-5
Dahm, T., and TEWORDT, L. (1995). PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y. Physica C Superconductivity 246, 61-72.
Dahm, T., & TEWORDT, L., 1995. PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y. Physica C Superconductivity, 246(1-2), p 61-72.
T. Dahm and L. TEWORDT, “PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y”, Physica C Superconductivity, vol. 246, 1995, pp. 61-72.
Dahm, T., TEWORDT, L.: PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y. Physica C Superconductivity. 246, 61-72 (1995).
Dahm, Thomas, and TEWORDT, L. “PHYSICAL QUANTITIES IN THE NORMAL AND D-WAVE SUPERCONDUCTING STATES OF THE HUBBARD-MODEL FOR YBA2CU3O7-Y”. Physica C Superconductivity 246.1-2 (1995): 61-72.