Quantum Phase Transition and Thermal Entanglement in the Isotropic XXX Model

Abstract

We investigate the quantum phase transition (QPT) and the pairwise thermal entanglement in the threequbit Heisenberg XXX chain with Dzyaloshinskii-Moriya (DM) interaction under a magnetic field. The ground states of the system exist crossing points, which shows that the system exhibits a QPT. At a given temperature, the entanglement undergoes two sudden changes (platform-like behavior) as the DM interaction or external magnetic field increases. This special property can be used as the entanglement switch, which is also influenced by the temperature. We can modulate the DM interaction or external magnetic field to control the entanglement switch.

Multipartite entanglement and quantum phase transitions in the XXZ model with Dzyaloshinskii–Moriya interaction

“…So, entanglement is viewed as the core resource of critical phenomena occurring in these systems; this has been proved in the detections of QPTs [7,8]. Subsequently, the connections between entanglement and critical properties have been widely investigated in condensed matter systems [3,4,6,[9][10][11][12][13][14][15][16][17][18][19][20][21]. In our opinion, there are two main motiv ations behind such work.…”

“…To date, pairwise entanglement, witnessed by concurrence or negativity, plays an important role in the characterization of QPTs [3,4,6,[9][10][11][12][13][14][15][16][17][18][19][20]. In addition, other measures of pairwise quantum correlation, such as quantum discord [19,20,35], geometric quantum discord [36], fidelity [37,38] and Bell inequality [36,39,40], have also been used to detect QPTs.…”