Abstract
We study zero temperature phase transitions in two classes of random quantum systems—the -state quantum Potts and clock models. For models with purely ferromagnetic interactions in one dimension, we show that for strong randomness there is a second order transition with critical properties that can be determined exactly by use of a renormalization group procedure. Somewhat surprisingly, the critical behavior is completely independent of . For the clock model, we suggest the existence of a novel multicritical point at intermediate randomness. We also consider the transition from a paramagnet to a spin glass in an infinite-range model, and find independent exponents.
- Received 20 October 1995
DOI:https://doi.org/10.1103/PhysRevLett.76.3001
©1996 American Physical Society