|M.Sc Student||Alexander Mihlin|
|Subject||Temperature Dependence of the Order Parameter of Cuprate|
|Department||Department of Physics||Supervisor||Full Professor Auerbach Assa|
|Full Thesis text|
A model of charged hole-pair bosons, with long range Coulomb interactions and very weak interlayer coupling, is used to calculate the order parameter of underdoped cuprates. Model parameters are extracted from experimental superfluid densities and plasma frequencies. The temperature dependence of the order parameter is characterized by a trapezoidal shape. At low temperatures, it declines slowly due to harmonic phase fluctuations which are suppressed by anisotropic plasma gaps. Above the single layer Berezinskii-Kosterlitz-Thouless temperature, the order parameter falls rapidly toward the three dimensional transition temperature. The theoretical curves are compared to c-axis superfluid density data and to transverse nodal velocity measured by angular resolved photoemission spectroscopy on Bi2Sr2CaCu2O8-δ samples.