Finite-temperature transition into a power-law spin phase with an extensive zero-point entropy.

We introduce an xy generalization of the frustrated Ising model on a triangular lattice. The presence of continuous degrees of freedom stabilizes a finite-temperature spin state with power-law discrete spin correlations and an extensive zero-point entropy. In this phase, the unquenched degrees of freedom can be described by a fluctuating surface with logarithmic height correlations. Finite-size Monte Carlo simulations have been used to characterize the exponents of the transition and the dynamics of the low-temperature phase. Typeset using REVTEX 1