The Partially-Split Hall Bar: Tunneling in the Bosonic Integer Quantum Hall Effect

摘要

We study point-contact tunneling in the integer quantum Hall state of bosons.This symmetry-protected topological state has electrical Hall conductivityequal to $2 e^2/h$ and vanishing thermal Hall conductivity. In contrast to theinteger quantum Hall state of fermions, a point contact can have a dramaticeffect on the low energy physics. In the absence of disorder, a point contactgenerically leads to a partially-split Hall bar geometry. We describe theresulting intermediate fixed point via the two-terminal electrical (Hall)conductance of the edge modes. Disorder along the edge, however, both restoresthe universality of the two-terminal conductance and helps preserve theintegrity of the Hall bar within the relevant parameter regime.