2006/03/13 by Lucia Canova, Jozef Strecka, Michal Jascur · 1 citation
Physics and Astronomy · #cond-mat.stat-mech #cond-mat.dis-nn
paper · pdf · doi:10.1088/0953-8984/18/20/020
published as J. Phys.: Condens. Matter 18 (2006) 4967-4984 · 19 pages, 11 figures, submitted to J. Phys.: Condens. Matter
arxiv created 2006/03/13 · arxiv updated 2009/12/01
Ground-state and finite-temperature properties of the mixed spin-1/2 and spin-S Ising-Heisenberg diamond chains are examined within an exact analytical approach based on the generalized decoration-iteration map. A particular emphasis is laid on the investigation of the effect of geometric frustration, which is generated by the competition between Heisenberg- and Ising-type exchange interactions. It is found that an interplay between the geometric frustration and quantum effects gives rise to several quantum ground states with entangled spin states in addition to some semi-classically ordered ones. Among the most interesting results to emerge from our study one could mention a rigorous evidence for quantized plateux in magnetization curves, an appearance of the round minimum in the thermal dependence of susceptibility times temperature data, double-peak zero-field specific heat curves, or an enhanced magnetocaloric effect when the frustration comes into play. The triple-peak specific heat curve is also detected when applying small external field to the system driven by the frustration into the disordered state.