Spin and charge dynamics of stripes in doped Mott insulators

We study spin and charge dynamics of stripes in doped Mott insulators by considering a two-dimensional Hubbard model with N fermion flavors. For N = 2 we recover the normal one-band model while for N → ∞ a spin density wave mean-field solution. For all band fillings, lattice topologies and N = 4n, the model may be solved by means of quantum Monte Carlo methods without encountering the sign problem. At N = 4 and in the vicinity of the Mott insulator we find a stripe phase. This phase has a quasiparticle gap but conducts due to long-wavelength low-lying collective charge modes.