Berry's phase in the multimode Peierls states
  It is shown that Berry's phase associated with the adiabatic change of local variables in the Hamiltonian can be used to characterize the multimode Peierls state, which has been proposed as a new type of the ground state of the two-dimensional(2D) systems with the electron-lattice interaction. 
Tohru Kawarabayashi, Yoshiyuki Ono, Chiduru Watanabe