Topological quantum phase transition in the BEC-BCS crossover phenomena
arXiv:1003.4735 · doi:10.1103/PhysRevB.82.073105
Abstract
A crossover between the Bose Einstein condensation (BEC) and BCS superconducting state is described topologically in the chiral symmetric fermion system with attractive interaction. Using a local Z_2 Berry phase, we found a quantum phase transition between the BEC and BCS phases without accompanying the bulk gap closing.
4 pages, 5 figures