The quasi-one-dimensional frustrated XY model

Publisher Website
Google Scholar
Abstract
A quasi-one-dimensional version of the frustrated XY model used to describe Josephson junction arrays and granular superconductors is described. It is shown that there are two distinct types of ground state, depending on whether the frustration is greater than or less than a critical amount. The small fluctuations around the weak frustration ground state are analysed by diagonalising the Hessian matrix; this gives an expression for the low-temperature specific heat of the network. By an extension of this analysis to include the effect of twisted boundary conditions, the critical current of the system is calculated in the low-flux regime. Finally the effect of diamagnetic screening currents is included.