Fig. 2
From: Sound-driven single-electron transfer in a circuit of coupled quantum rails
Directional-coupler operation. a Schematic slices along the double-well potential, \(U\). The horizontal lines represent the eigenstates in the moving QD, whereas the grey shading of the energy levels indicates the exponentially decreasing occupation. b Schematic showing the QDs that are formed by the SAW in the coupling region with additional indications of the surface gates and the transport paths. The black vertical bar indicates the positions of the aforementioned potential slices. c Probability, \(P\), to end up in the upper (U) or lower (L) quantum rail for different values of potential detuning, \(\Delta\). The lines show a fit by a Fermi function providing the scale parameter, \(\sigma\). d Transition widths, \(\sigma\), for different values of the tunnel-barrier voltage, \({V}_{{\rm{T}}}\). The line shows the course of a stationary, one-dimensional model of the partitioning process
