Entanglement of several blocks in fermionic chains
  In this paper we propose an expression for the entanglement entropy of several intervals in a stationary state of a free, translational invariant Hamiltonian in a fermionic chain. We check numerically the accuracy of our proposal and conjecture a new formula for the asymptotic behaviour of principal sub-matrices of a Toeplitz matrix. 
F. Ares, J. G. Esteve, F. Falceto
quant-ph cond-mat.stat-mech math-ph math.MP