Imaging One-Electron Quantum Dots in InAs/InP Nanowires*

Quantum dots formed in InAs/InP heterostructure nanowires are attractive candidates for nanoelectronics, spintronics, and quantum information processing. It has been shown that with the use of a liquid helium cooled scanning probe microscope (SPM) the electronic charge state of a single quantum dot can be chosen by merely moving the tip of the SPM with respect to the dot [1]. Simulations show that this technique can also be implemented for double quantum dots with interdot separation less than 30nm. By applying a magnetic field the electronic states of a quantum dot can be spin split. It is possible to image this splitting with the local, movable electrostatic gating of the SPM. A magnetic field applied to a double dot system can be used to create a spin filter; a simple movement of the SPM tip with respect to the dot structure can determine which spin passes through the filter. \newline [1] A. Bleszynski et al., 28th Int. Conf. Physics of Semiconductors, 2006.