Tuning directional dependent metal–insulator transitions in quasi-1D quantum wires with spin–orbit density wave instability

Abstract

We study directional dependent band gap evolutions and metal–insulator transitions (MITs) in model quantum wire systems within the spin–orbit density wave (SODW) model. The evolution of MIT is studied as a function of varying anisotropy between the intra-wire hopping () and inter-wire hopping () with Rashba spin–orbit coupling. We find that as long as the anisotropy ratio () remains below 0.5, and the Fermi surface nesting is tuned to , an exotic SODW induced MIT easily develops, with its critical interaction strength increasing with increasing anisotropy. As (2D system), the nesting vector switches to , making this state again suitable for an isotropic MIT. Finally, we discuss various physical consequences and possible applications of the directional dependent MIT.