Linear entropy of purity as indicators of quantumness and criticality in a Spin-1/2 Ising–Heisenberg diamond chain

In this article, exploiting the notion of the resource theory of purity, we introduce a nonclassical correlation measure defined as the difference between the purity of a quantum state and its counterpart. It is demonstrated that the proposed purity-based measure is a faithful measure of nonclassical correlation. Harnessing the above proposed nonclassical measure, we investigate the behavior of quantum correlations and critical phenomena in a spin-1/2 Ising–Heisenberg diamond chain in the presence of Dzyaloshinskii–Moriya (DM) interaction. We analyze the ground-state phase diagram of the system and demonstrate that the DM interaction significantly expands the entangled region. By constructing the thermal state of the spin-1/2 Ising–Heisenberg diamond chain, we investigate the quantum correlations of the physical system under consideration. Furthermore, we explore phase transitions in the spin-1/2 Ising–Heisenberg diamond chain from the perspective of quantum information theory focusing on quantum correlations as a tool. The impact of DM interaction and other system parameters on nonclassicality and quantum criticality have also been brought out.