Insulating-to-conducting state transition in the bilayer Hubbard model induced by a perpendicular quench field

TL;DR

This paper studies how a perpendicular electric field can induce a transition from an insulating to a conducting state in a bilayer Hubbard model, revealing a resonance-driven mechanism for conductivity in strongly correlated systems.

Contribution

It uncovers a novel dynamic transition mechanism driven by a resonant electric field, highlighting the cooperative effect of interactions and external fields in strongly correlated materials.

Findings

Steady state conductivity occurs at resonance with on-site repulsion.

Both layers become conducting due to long-lived dopings.

The transition is driven by interplay between interactions and the electric field.

Abstract

A many-body quantum system with varying parameters can exhibit two distinct quantum states within the same energy shell. This allows for a dynamic transition from the ground state of the pre-quench Hamiltonian to a steady state of the post-quench Hamiltonian. We investigate the dynamic response of the ground states in a two-layer half-filled Hubbard model to a perpendicular electric field. We demonstrate that the steady state exhibits conductivity when the field is in resonance with the on-site repulsion, while the initial state is a Mott-insulating state. Additionally, the two layers exhibit identical conducting behavior due to the formation of long-lived dopings, as evidenced by the charge fluctuation. The key factor in achieving this dynamic transition is the cooperative interplay between on-site interactions and the resonant field, rather than the individual roles they play. Our findings offer an alternative mechanism for field-induced conductivity in strongly correlated systems.