Pair phase fluctuations and the pseudogap

The single-particle density of states and the tunneling conductance are studied for a two-dimensional BCS-like Hamiltonian with a d(x)(2)-y(2)-gap and phase fluctuations. The latter are treated by a classical Monte Carlo simulation of an XY model. Comparison of our results with recent scanning tunneling spectra of Bi-based high-T-c cuprates supports the idea that the pseudogap behavior observed in these experiments can be understood as arising from phase fluctuations of a d(x)(2)-y(2) pairing gap whose amplitude forms on an energy scale set by T-c(MF) well above the actual superconducting transition.