Staggered Long-Range Order for Diluted Quantum Spin Models

We study an annealed site diluted quantum XY model with spin S∈12N\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$S\in \tfrac{1}{2}{\mathbb {N}}$$\end{document}. We find regions of the parameter space where, in spite of being a priori favourable for a densely occupied state, phases with staggered occupancy occur at low temperatures.