Abstract
We use renormalization-group theory to examine the quantum phase transitions upon exiting the insulating phase of a disordered, strongly interacting boson system. For weak disorder we find a direct transition from this Mott insulator to the superfluid phase. In a finite region around the particle-hole symmetric point supports this direct transition, whereas for perturbative arguments suggest that the direct transition survives only precisely at commensurate filling. For strong disorder the renormalization trajectories pass next to two fixed points, describing a pair of distinct transitions; first from the Mott insulator to the Bose glass, and then from the Bose glass to the superfluid. The latter fixed point possesses statistical particle-hole symmetry and a dynamical exponent , equal to the dimension .
- Received 18 August 1997
DOI:https://doi.org/10.1103/PhysRevB.57.5044
©1998 American Physical Society