arXiv:0801.0414 · Journal of Physics Condensed Matter
External electric field mediated quantum phase transitions in one-dimensional charge-ordered insulators: a density matrix renormalization group study
Sudipta Dutta, Swapan K Pati
Abstract
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 >2 V ) and CDW ( U <2 V ) 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.