Geometric frustration in the class of exactly solvable Ising-Heisenberg diamond chains

TL;DR

This paper provides an exact analytical study of the ground-state and finite-temperature properties of mixed spin-1/2 and spin-S Ising-Heisenberg diamond chains, highlighting the role of geometric frustration in inducing quantum and semi-classical states.

Contribution

It introduces an exact analytical approach to analyze the effects of geometric frustration in Ising-Heisenberg diamond chains, revealing new quantum states and thermodynamic phenomena.

Findings

Quantized magnetization plateaus observed.

Double-peak specific heat curves detected.

Enhanced magnetocaloric effect due to frustration.

Abstract

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.