A heuristic theory of the spin glass phase

We study the low-temperature phase of the nearest-neighbor Ising spin glass. Our analysis of gauge-invariant ground state Peierls contours suggests the existence of infinitely many disjoint Gibbs states at low temperatures, provided the dimension,d, is sufficiently large (presumablyd> 3 or 4), while ford=2 the Gibbs state is unique for all temperatures. Ind 3 we present arguments supporting the existence of a massless phase with broken spin-flip symmetry at low temperatures.