Chirality transition of XY model on three-layer triangular lattice

We investigate phase transitions of XY model on a three-layer triangular lattice by assuming that the intralayer interactions on the first and the third layer are antiferromagnetic and the one on the second layer ferromagnetic. We use Monte Carlo simulations and find that there are two critical temperatures Tcl and Tcu (Tclcritical phenomena is clarified by means of finite-size scaling analysis.