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arXiv · 1511.05382

Field induced multiple order-by-disorder state selection in antiferromagnetic honeycomb bilayer lattice

F. A. Gómez Albarracín·H. D. Rosales
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Abstract

In this paper we present a detailed study of the antiferromagnetic classical Heisenberg model on a bilayer honeycomb lattice in a highly frustrated regime in presence of a magnetic field. This study shows strong evidence of entropic order-by-disorder selection in different sectors of the magnetization curve. For antiferromagnetic couplings $J_1=J_x=J_p/3$, we find that at low temperatures there are two different regions in the magnetization curve selected by this mechanism with different number of soft and zero modes. These regions present broken $Z_2$ symmetry and are separated by a not fully collinear classical plateau at $M=1/2$. At higher temperatures, there is a crossover from the conventional paramagnet to a cooperative magnet. Finally, we also discuss the low temperature behavior of the system for a less frustrated region, $J_1=J_x<J_p/3$.

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F. A. Gómez Albarracín, H. D. Rosales. 2016-03-29. Field induced multiple order-by-disorder state selection in antiferromagnetic honeycomb bilayer lattice. https://doi.org/10.1103/physrevb.93.144413

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