Unidirectional Charge Transport via Ripplonic Polarons in a Three-Terminal Microchannel Device.

We study the transport of surface electrons on superfluid helium through a microchannel structure in which the charge flow splits into two branches, one flowing straight and one turned at 90 degrees. According to Ohm's law, an equal number of charges should flow into each branch. However, when the electrons are dressed by surface excitations (ripplons) to form polaronlike particles with sufficiently large effective mass, all the charge follows the straight path due to momentum conservation. This surface-wave induced transport is analogous to the motion of electrons coupled to surface acoustic waves in semiconductor 2DEGs.