External Electric Field Mediated Quantum Phase Transitions in One-Dimensional Charge Ordered Insulators: A DMRG Study

TL;DR

This study uses DMRG calculations to explore how external electric fields induce phase transitions in one-dimensional charge-ordered insulators, revealing differences in transition thresholds between SDW and CDW states.

Contribution

It provides a detailed analysis of electric field-induced phase transitions in 1D charge-ordered insulators, highlighting the dependence on Coulomb interactions and system size.

Findings

CDW insulators require higher bias than SDW for insulator-metal transition.

External electric field induces phase transitions between SDW and CDW states.

Transition thresholds decrease with increasing system size.

Abstract

We perform density matrix renormalization group (DMRG) 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 field. 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 transition at zero temperature. We also find the CDW-SDW phase transition on application of external electric field. The bias required for the transitions in both cases decreases with increase in system size.