Order Parameter Symmetry in Doped YBCO Systems

Abstract

Intense experimental and theoretical efforts have recently been brought to bear on the determination of the symmetry of superconducting order parameter in high T${}_c$ Cuprates as this would shed light on the nature of microscopic interactions that are responsible for superconductivity in these unusual systems. We use a two band model that reproduces the Fermi surface seen in ARPES experiments of Shen et al., and study the symmetry of order parameter in the YBCO system. The model incorporates the effects of tunnelling in the c-direction between the planes and chains of these Cuprates. It is observed that a suitable choice of the phase of the pair wave-function in the planes and chains lead to both s- and d-wave like features. We calculate the detailed phase diagram of this system, observe the shift in the position of the node(s) of the order parameter(s) on the Fermi surface with doping and explain the seemingly contradictory experimental observations about the presence of both s- and/or d-wave symmetry in these systems.

11 pages, 4 Postscript figures, Latex. Minor typographical changes

References in corpus (4)

• Coupling between planes and chains in YBa2Cu3O7 : a possible solution for the order parameter controversy
• New features in the microwave response of YBCO crystals: Evidence for a multi-component order parameter
• Phenomenological BCS theory of the high-$T_c$ cuprates
• Fluctuation Effects And Order Parameter Symmetry In The Cuprate Superconductors

Cited by in corpus (1)

• Gap anisotropy in the angle-resolved photoemission spectroscopy of Bi_2Sr_2CaCu_2O_{8+δ}