We analyze a quantum spin Hall (QSH) device with a point contact connecting two of its edges. The contact supports a net spin tunneling current that can be probed experimentally via a two-terminal resistance measurement. We find that the low-bias tunneling current and the differential conductance exhibit scaling with voltage and temperature that depend nonlinearly on the strength of the electron-electron interaction.
@article{arxiv.0811.3222,
title = {Tunneling between edge states in a quantum spin Hall system},
author = {Anders Ström and Henrik Johannesson},
journal= {arXiv preprint arXiv:0811.3222},
year = {2009}
}