Electronic structures in single self-assembled InAs quantum dashes detected by nanogap metal electrodes

We have investigated electronic structures in single self-assembled InAs quantum dashes (QDHs) coupled to metal nanogap electrodes. The fabricated QDH samples operate as single electron transistors, exhibiting high differential conductances as well as small charging/orbital quantization energies for large electron numbers. In the few electron regimes, the conductance and addition energies strongly depend on the number of the electrons. Calculation of electronic properties by spin-density-functional theory reveals that electron transport is affected by a drastic change in the electronic orbital shape. These transport properties are intrinsic to InAs QDH structures with a highly anisotropic wire-like shape. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3659479]