  Research focused on heat transport in the quantum Hall (QH) edge channel has
successfully addressed fundamental theoretical questions surrounding the QH
physics. However, the picture of the edge channel is complicated by the
phenomenon of energy dissipation out of the edge, and theories treating this
dissipation are lacking. More experimental data is also needed to determine the
coupling mechanism by which energy leaves the edge channel. We developed a
method to map the heat transport in the QH edge to study the dissipation of
heat. We locally heated the QH edge and locally detected the temperature
increase while continuously varying the distance between heater and
thermometer. We thereby obtained the thermal decay length of the edge state.
