Phase diagram of the K1-K2 Kitaev model. Monte Carlo simulations and thermal fluctuations

JUAN IGNACIO PICCININI; F. A. GÓMEZ ALBARRACÍN ; H.D. ROSALES

La Plata

Congreso; 102a Reunión de la Asociación Física Argentina; 2017

Asociación Física Argentina

Frustration has proved to give rise to an extremely rich phenomenology in both quantum and classical systems. The inclusion of an external magnetic field could change the degeneracy and topology of the ground state manifold stabilizing different ground states.Motivated by this, in this work we present a study of the Kitaev K1-K2 model in a honeycomb lattice in the presence of an external magnetic field. Rousochatzakis et. al [PRB 2016] has studied the case without an external field, showing that the presence of Kitaev interactions between next-nearest neighbors offers a suitable explanation to the order observed in the Na2IrO3 material at low temperatures.Recently, due to the anisotropy introduced by the Kitaev interactions, the existence of exotic phases has been observed depending on the direction of the external field. Therefore we are seeking to explore the phase diagram of the Kitaev K1-K2 model in the presence of a magnetic field and to contrast this with the results obtained in the Heisenberg-Kitaev model. Using Monte Carlo simulations and analytic calculus of Gaussian fluctuations, we analyze the stability of the phases at low temperature and the possible mechanisms of selection of order phases.