arXiv:quant-ph/0403099 · Physical Review A
Representation of the SO(3) group by a maximally entangled state
W. LiMing, Zhilie Tang, Cai-Hong Liao
Abstract
A representation of the $\mathrm{SO}(3)$ group is mapped into a maximally entangled two qubit state according to the literature. To show the evolution of the entangled state, a model is set up on an maximally entangled electron pair, two electrons of which pass independently through a rotating magnetic field. It is found that the evolution path of the entangled state in the $\mathrm{SO}(3)$ sphere breaks an odd or even number of times, corresponding to the double connectedness of the $\mathrm{SO}(3)$ group. An odd number of breaks leads to an additional $\ensuremath{\pi}$ phase to the entangled state, but an even number of breaks does not. A scheme to trace the evolution of the entangled state is proposed by means of entangled photon pairs and Kerr medium, allowing observation of the additional $\ensuremath{\pi}$ phase.