arXiv:1303.1623 · Physical Review A
Unifying geometric entanglement and geometric phase in a quantum phase transition
Vahid Azimi Mousolou, C. M. Canali, Erik Sjöqvist
Abstract
Geometric measure of entanglement and geometric phase have recently been used to analyze quantum phase transition in the $XY$ spin chain. We unify these two approaches by showing that the geometric entanglement and the geometric phase are respectively the real and imaginary parts of a complex-valued geometric entanglement, which can be investigated in typical quantum interferometry experiments. We argue that the singular behavior of the complex-value geometric entanglement at a quantum critical point is a characteristic of any quantum phase transition, by showing that the underlying mechanism is the occurrence of level crossings associated with the underlying Hamiltonian.