Specific heat study on a spin-one-half frustrated diamond chain

The specific heat of S=1/2S=1/2 frustrated diamond-spin chain has been examined by means of the Green's function theory combined with the Jordan–Wigner transformation, and the particular emphasis is laid on the investigation of the effect of geometric frustration, which is generated by the competition between the exchange interactions along the spin chain. It is found that the interplay between the geometric frustration and quantum effects gives rise to non-trivial behaviors in the curves of the specific heat: in the absence of the external magnetic field, the temperature dependence of the specific heat shows a double-peak structure for different strength of the frustration, and in the presence of the external field, the curves of the specific heat display as a three-peak structure due to the field-induced splitting of the energy levels related to the frustrated spins, which are in good agreement with the exact analytical approach based on the generalized decoration–iteration map method.