Multiple pseudo-plateaux states and antiferromagnetic pair selection in the XY model in the highly frustrated honeycomb lattice

F. A. GÓMEZ ALBARRACÍN; H. D. ROSALES

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 2021

0953-8984

We present a study of the low temperature magnetic phases of theclassical XY model with third nearest neighbor interactions on the honeycomblattice at the maximally frustrated point under an external magnetic field byextensive Monte Carlo simulations. We focus on the characterization of theemergent low temperature phases, which are a direct consequence of the unusuallyhigh numbers of spins per plaquette in the model. Specifically, we show that,since thermal fluctuations partially lift the ground-state degeneracy and selectthe most collinear states, the selected states are those with the highest numberof ?antiferromagnetic pairs? (AFp) compatible with the external magnetic field.These AFp are formed in such a way that they maximize the degeneracy of theselected submanifold of ground states. Moreover, two collinear pseudoplateauxemerge at M = 1/3 and M = 2/3. To characterize the magnetization process,we employ Monte Carlo simulations and calculate relevant order parameters toconstruct the complete temperature vs. magnetic field phase diagram.