Twodimensionally distributed Model for HEB based on Random Phase Transitions

摘要

According to AFM measurements, ultrathin NbN films are not smooth but exhibit a more or less random distribution of microcrystallites. This gives rise to a superconducting to normal conducting phase transition that follows a first order percolation phase transition. Such a phase transition is easily described by a single critical exponent justifying the assumption of a simple, local R(T) curve used in all distributed HEB models.