Magnetic Field induced order by disorder state selection in the classical bilayer honeycomb lattice

F. GÓMEZ ALBARRACÍN

Natal

Workshop; Latin American Workshop in condensed matter: low dimensional topological condensed matter; 2015

International Institute of Physics - Universidad Federal de Río Grande del Norte

(talk) We present a thorough study of a classical magnetic spin system: the bilayer honeycomb lattice with frustrating interlayer couplings. We show that in some particular cases this system is highly frustrated and has a degenerate ground state. We study through Monte Carlo simulations its behaviour with temperature under an external magnetic field. We find that, depending on this field, different states are selected from the ground state manifold through the order by disorder mechanism. We study different parameters to define the selected states, broken symmetries and phase transitions, and present the h-T phase diagram. Using  analytical calculations and the specific heat curve we show that there are soft and zero modes in the thermal fluctuations of different states, which give rise to their selection due to order by disorder.