Emergent Geometric Hamiltonian and Insulator-Superfluid Phase Transitions

Fei Zhou

Published 2005-03-22, updated 2005-05-05Version 2

I argue that certain bosonic insulator-superfluid phase transitions as an interaction constant varies are driven by emergent geometric properties of insulating states. The {\em renormalized} chemical potential and distribution of disordered bosons define the geometric aspect of an effective low energy Hamiltonian which I employ to study various resonating states and quantum phase transitions. In a mean field approximation, I also demonstrate that the quantum phase transitions are in the universality class of a percolation problem.