We use the voltage biased tip of a scanning force microscope at a temperature of 35\,mK to locally induce the fractional quantum Hall state of ν=1/3 in a split-gate defined constriction. Different tip positions allow us to vary the potential landscape. From temperature dependence of the conductance plateau at G=1/3×e2/h we determine the activation energy of this local ν=1/3 state. We find that at a magnetic field of 6\,T the activation energy is between 153\,μeV and 194\,μeV independent of the shape of the confining potential, but about 50\% lower than for bulk samples.
@article{arxiv.1603.03567,
title = {Investigating Energy Scales of Fractional Quantum Hall States using Scanning Gate Microscopy},
author = {Beat A. Braem and Tobias Krähenmann and Szymon Hennel and Christian Reichl and Werner Wegscheider and Klaus Ensslin and Thomas Ihn},
journal= {arXiv preprint arXiv:1603.03567},
year = {2016}
}