Properties of high temperature superconductors in states of mixed symmetry

Abstract

We study the properties of high temperature superconductors (HTSs) in the states of mixedsymmetry with coexisting d- and s-wave order parameter components. We model the mixedsymmetry states of the HTSs in the framework of two-order-parameter Ginzburg–Landau (GL)theory. We solve the coupled nonlinear GL equations using a high precision exact numericaliteration technique for the entire range of applied magnetic field, arbitrary GL parameterκ and vortex lattice symmetry. We study theoretically and compare with experimentsseveral properties of HTSs, such as local spatial behaviors of the magnetic field andorder parameter profiles, vortex core radius, penetration depth of the magneticfield, structure of the vortex lattice, reversible magnetization, upper critical fieldHc2 and shear modulus of the vortex lattice, and their variations with temperature and appliedmagnetic field. The excellent agreement between theoretical and experimental results onHTSs shows that the mixed symmetry scenario is a good candidate for the description ofthe HTSs.