Supersymmetric Quantum Spherical Spins with Short-Range Interactions

This work is dedicated to the study of a supersymmetric quantum spherical spin system with short-range interactions. We examine the critical properties both a zero and finite temperature. The model undergoes a quantum phase transition at zero temperature without breaking supersymmetry. At finite temperature the supersymmetry is broken and the system exhibits a thermal phase transition. We determine the critical dimensions and compute critical exponents. In particular, we find that the model is characterized by a dynamical critical exponent $z=2$. We also investigate properties of correlations in the one-dimensional lattice. Finally, we explore the connection with a nonrelativistic version of the supersymmetric $O(N)$ nonlinear sigma model and show that it is equivalent to the system of spherical spins in the large $N$ limit.
Comment: 33 pages, 10 figures, typos fixed, new discussions included, published version