Quantum discord and quantum phase transition in spin-1/2 frustrated Heisenberg chain (pp0452-0468)
          Chu-Hui Fan, Heng-Na Xiong, Yixiao Huang, and Zhe Sun
          doi: https://doi.org/10.26421/QIC13.5-6-6
Abstracts: By using the concept of the quantum discord (QD), we study the spin-1/2 antiferromagnetic Heisenberg chain with next-nearest-neighbor interaction. Due to the 𝑆𝑈(2) symmetry and 𝑍2 symmetry in this system, we obtain the analytical result of the QD and its geometric measure (GMQD), which is determined by the two-site correlators. For the 4-site and 6-site cases, the connection between GMQD (QD) and the eigenenergies was revealed. From the analytical and numerical results, we find GMQD (QD) is an effective tool in detecting both the first-order and the infinite-order quantum-phase-transition points for the finite-size systems. Moreover, by using the entanglement excitation energy and a universal frustration measure we consider the frustration properties of the system and find a nonlinear dependence of the GMQD on the frustration.
Key words: geometric measure of quantum discord, quantum phase transition, frustration