Implementation of quantum gates based on geometric phases accumulated in   the eigenstates of periodic invariant operators
  We propose a new strategy to physically implement a universal set of quantum gates based on geometric phases accumulated in the nondegenerate eigenstates of a designated invariant operator in a periodic physical system. The system is driven to evolve in such a way that the dynamical phase shifts of the invariant operator eigenstates are the same (or {\it mod} $2\pi$) while the corresponding geometric phases are nontrivial.   We illustrate how this strategy to work in a simple but typical NMR-type qubit system. 
L. B. Shao, Z. D. Wang, and D. Y. Xing