  Quantum energy teleportation (QET) is a proposed protocol related to the
quantum vacuum. The edge channels in a quantum Hall system is well suited for
the experimental verification of QET. For this purpose, we examine a charge
density wave excited and detected by capacitively coupled front gate
electrodes. We observe the waveform of the charge density wave, which is
proportional to the time derivative of the applied square voltage wave.
Further, we study the transmission and reflection behaviors of the charge
density wave by applying a voltage to another front gate electrode to control
the path of the edge state. We show that the threshold voltages where the
dominant direction is switched in either transmission or reflection for dense
and sparse waves are different from the threshold voltage where the current
stops flowing in an equilibrium state.
