Journal of the Korean Physical Society
A signature of the quantum phase transition in a hard-core boson model in one dimension
Gi Wook Shin, Ji-Woo Lee
Abstract
We study quantum phase transitions in a hard-core boson model with nearest-neighbor repulsions in one dimension. As we change the repulsive energy, V , between bosons occupying nearest neighbors, the model exhibits a quantum phase transition from a superfluid (SF) to a charge-density-wave (CDW)-type solid phase at half-filling. By using an exact diagonalization method with a modified Lanczos method, we calculate the ground-state energies up to a precision of O (10 −7 ). From the ground-state energies, we obtain the number of dimers by taking numerical derivatives of the groundstate energies. Because the dissolution of the dimers occurs because of the repulsive energy, V , we find a signature of the quantum phase transition from the behaviors of the correlation energy and those of the number of dimers as a function of V .