Stable Branched Electron Flow

TL;DR

This paper investigates the robustness of branched electron flow patterns in ballistic systems, showing they persist despite significant changes in electron density but are sensitive to background potential variations.

Contribution

It demonstrates that branched electron flow patterns are resilient to electron density changes but affected by background potential alterations, revealing new insights into electron trajectory stability.

Findings

Pattern persists with reduced electron density

Pattern is sensitive to background potential changes

Branch pattern remains stable under certain conditions

Abstract

The pattern of branched electron flow revealed by scanning gate microscopy shows the distribution of ballistic electron trajectories. The details of the pattern are determined by the correlated potential of remote dopants with an amplitude far below the Fermi energy. We find that the pattern persists even if the electron density is significantly reduced such that the change in Fermi energy exceeds the background potential amplitude. The branch pattern is robust against changes in charge carrier density, but not against changes in the background potential caused by additional illumination of the sample.