Phase Transitions for Cuboc Orders in Stacked Kagome Heisenberg Systems

TL;DR

This study uses advanced Monte Carlo simulations to analyze phase transitions in stacked Kagome Heisenberg systems, revealing distinct transition behaviors for two complex non-coplanar spin orders, cuboc1 and cuboc2.

Contribution

It provides the first detailed Monte Carlo analysis of phase transitions for cuboc orders in stacked Kagome systems, highlighting their transition types and connection to Landau-Ginzburg-Wilson theory.

Findings

Cuboc1 transition shows weak second-order to first-order behavior.

Cuboc2 transition is primarily first-order.

Transitions relate to O(3)xO(3) symmetry in effective theory.

Abstract

Using the event-chain Monte Carlo (MC) algorithm, we investigate phase transitions of the stacked Kagome Heisenberg systems with classical vector spins including up to the 3rd-nearest-neighbor couplings. In particular, we focus on two types of non-coplanar spin orders ---cuboc1 and cuboc2 orders, both of which have twelve-sublattice structures accompanying the translational-symmetry breaking. We perform event-chain MC simulations up to L=72, where L represents the linear dimension of the stacked Kagome lattice, and then find that the cuboc1 transition shows 2nd-order-transition behaviors with a tendency to a weak-1st-order transition up to L=72, while the cuboc2 transition is basically described by the 1st-order transition. We then discuss the above transitions in connection with the effective Landau-Ginzburg-Wilson theory with the O(3)xO(3) symmetry.