Environment assisted superballistic scaling of conductance

TL;DR

This paper demonstrates that weak environmental effects can induce superballistic conductance scaling at band-edges in tight-binding chains, a phenomenon absent in isolated systems, due to interplay of incoherence and exceptional points.

Contribution

It reveals environment-assisted superballistic conductance scaling at band-edges, expanding understanding of transport in open quantum systems.

Findings

Conductance exhibits power-law growth with system length at band-edges.

Superballistic scaling can be extended by reducing environmental coupling.

No similar behavior occurs in isolated systems.

Abstract

We find that, in the presence of weak incoherent effects from surrounding environments, the zero temperature conductance of nearest neighbour tight-binding chains exhibits a counter-intuitive power-law growth with system length at band-edges, indicating superballistic scaling. This fascinating environment assisted superballistic scaling of conductance occurs over a finite but extended regime of system lengths. This scaling regime can be systematically expanded by decreasing the coupling to the surrounding environments. There is no corresponding analog of this behavior for isolated systems. This superballistic scaling stems from an intricate interplay of incoherent effects from surrounding environments and exceptional points of the system's transfer matrix that occur at every band-edge.