Transport anisotropy and metal-insulator transition in striped Dirac fermion systems

TL;DR

This study uses quantum Monte Carlo simulations to explore how charge density stripes induce anisotropic transport and phase transitions in a 2D Dirac fermion system, revealing potential experimental control over electronic properties.

Contribution

It demonstrates how charge stripes affect transport anisotropy and phase transitions in interacting Dirac fermions, including the transition from Mott insulator to metal.

Findings

Stripe induces transport anisotropy and an insulating intermediate phase.

Charge stripes compete with Coulomb repulsion, affecting the energy gap and magnetic order.

System can transition from Mott insulator back to metallic state.

Abstract

Using the determinant quantum Monte Carlo method, we investigate the metal-insulator transitions induced by the stripe of charge density in an interacting two-dimensional Dirac fermion system. The stripe will introduce the transport anisotropy and insulating intermediate phase into the system, accompanied by the change of band structure and a peak of density of states around Fermi energy. In the case of strong correlation, stripe exhibits competition with Coulomb repulsion through closing the energy gap and disrupting the magnetic order, and finally drives the system in Mott insulating phase back to the metallic state. Our results may provide a feasible way to modify transport properties by setting charge stripes in experiments.