We study the injection mechanism of a single electron from a static quantum
dot into a moving quantum dot created in a long depleted channel with surface
acoustic waves (SAWs). We demonstrate that such a process is characterized by
an activation law with a threshold that depends on the SAW amplitude and the
dot-channel potential gradient. By increasing sufficiently the SAW modulation
amplitude, we can reach a regime where the transfer is unitary and potentially
adiabatic. This study points at the relevant regime to use moving dots in
quantum information protocols.Comment: 5 pages, 4 figure
