Use of quantum dots as a switch for single-electron transfer free from cotunneling

Based on symmetry constraint that leads to the appearance of nodes in the wave functions of 3-electron systems at regular triangle configurations, it was found that, if the parameters of confinement are skillfully chosen and if a magnetic field is tuned around the first critical point of the single-triplet transition, a 2-electron quantum dot can be used as a switch for single-electron transport free from cotunneling.