Variational Matrix Product Ansatz for Nonuniform Dynamics in the   Thermodynamic Limit
  We describe how to implement the time-dependent variational principle for matrix product states in the thermodynamic limit for nonuniform lattice systems. This is achieved by confining the nonuniformity to a (dynamically growable) finite region with fixed boundary conditions. The suppression of unphysical quasiparticle reflections from the boundary of the nonuniform region is also discussed. Using this algorithm we study the dynamics of localized excitations in infinite systems, which we illustrate in the case of the spin-1 anti-ferromagnetic Heisenberg model and the $\phi^4$ model. 
Ashley Milsted, Jutho Haegeman, Tobias J. Osborne, Frank Verstraete
cond-mat.str-el quant-ph