External electric field mediated quantum phase transitions in one-dimensional charge-ordered insulators: a density matrix renormalization group study

We perform density matrix renormalization group calculations extensively on one-dimensional chains with on-site (U) as well as nearest-neighbour (V) Coulomb repulsions. The calculations are carried out in full parameter space with explicit inclusion of the static bias and we compare the nature of spin-density-wave (SDW) and charge-density-wave (CDW) insulators under the influence of external electric fields. We find that, although the SDW (U>2V) and CDW (U<2V) insulators enter into a conducting state after a certain threshold bias, CDW insulators require much higher bias than the SDW insulators for insulator-metal transitions at zero temperature. We also find the CDW-SDW phase transition on application of an external electric field. The bias required for the transitions in both cases decreases with increase in system size