Ising critical behaviour in the one-dimensional frustrated quantum XY model
Enzo Granato
Abstract
A generalization of the one-dimensional frustrated quantum XV model is considered in whiell the inter and intraechain coupling constarás of the two mfinite XV (planar rotor) chains have different strengths. The mudei can describe Lhe superconductor-insulator transitron due to chargtng effects in a ladder of Josephson junctions ia a magnetic field with Italf a flux quantum per pliaquet te. From a fluctuation- effective action, this transition is expected to Fie iii the universality class of Lhe two dimensional classical XY-Ising modei. rilhe criticai behaviour is studiral using a Monte Cano transfer erratrix applied to Lhe path-integral representation of the model and a finte sie scaling analysis of data on srnall system sues. II i found that, unlike the previous stirdied case of equal inter and intra chain roupling constai-as, Lhe XV and Ising like excitations of the quantum model decouple for large interchain coupling, giving rise to pule Ising mudei criticai behaviour for lhe chiratity order parameter in good agreement with Lhe results for Lhe XY-Ising modal.