Implementation of holonomic quantum gates by an isospectral deformation   of an Ising dimer chain
  We exactly construct one- and two-qubit holonomic quantum gates in terms of isospectral deformations of an Ising model Hamiltonian. A single logical qubit is constructed out of two spin-1/2 particles; the qubit is a dimer. We find that the holonomic gates obtained are discrete but dense in the unitary group. Therefore an approximate gate for a desired one can be constructed with arbitrary accuracy. 
Yukihiro Ota, Masamitsu Bando, Yasusi Kondo, and Mikio Nakahara