Quantum phase transition in the Dzyaloshinskii-Moriya interaction with inhomogeneous magnetic field: Geometric approach

In this paper, we generalize the results of Oh (Phys Lett A 373: 644-647, 2009) to Dzyaloshinskii-Moriya model under non-uniform external magnetic field to investigate the relation between entanglement, geometric phase (or Berry phase) and quantum phase transition. We use quaternionic representation to relate the geometric phase to the quantum phase transition. For small values of DM parameter, the Berry phase is more appropriate than the concurrence measure, while for large values, the concurrence is a good indicator to show the phase transition. On the other hand, by increasing theDMinteraction the phase transition occurs for large values of anisotropy parameter. In addition, for small values of magnetic field the concurrence measure is appropriate indicator for quantum phase transition, but for large values of magnetic field the Berry phase shows a sharp changes in the phase transition points. The results show that the Berry phase and concurrence form a complementary system from phase transition point of view.