Non-equilibrium electronic transport in a one-dimensional Mott insulator

TL;DR

This paper investigates how a one-dimensional Mott insulator transitions to a conducting state under strong bias voltage, revealing a universal current-voltage relationship and characterizing the breakdown process through advanced simulations.

Contribution

It provides a detailed analysis of non-equilibrium transport in a 1D Mott insulator, establishing a universal current-voltage dependence and linking the breakdown threshold to the Lieb-Wu gap.

Findings

Steady-state current exhibits a universal voltage dependence.

Breakdown threshold related to the Lieb-Wu gap.

Characterization of the breakdown state via double occupancy and entanglement entropy.

Abstract

We calculate the non-equilibrium electronic transport properties of a one-dimensional interacting chain at half filling, coupled to non-interacting leads. The interacting chain is initially in a Mott insulator state that is driven out of equilibrium by applying a strong bias voltage between the leads. For bias voltages above a certain threshold we observe the breakdown of the Mott insulator state and the establishment of a steady-state electronic current through the system. Based on extensive time-dependent density matrix renormalization group simulations, we show that this steady-state current always has the same functional dependence on voltage, independent of the microscopic details of the model and relate the value of the threshold to the Lieb-Wu gap. We frame our results in terms of the Landau-Zener dielectric breakdown picture. Finally, we also discuss the real-time evolution of the current, and characterize the current-carrying state resulting from the breakdown of the Mott insulator by computing the double occupancy, the spin structure factor, and the entanglement entropy.