Scanning gate imaging of quantum dots in 1D ultra-thin InAs/InP nanowires
Boyd, Erin E; Storm, Kristian; Samuelson, Lars; Westervelt, Robert M; Boyd, Erin E; Department of Physics, Harvard University, Cambridge, MA 02138, USA; Storm, Kristian; Solid State Physics/the Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund, Sweden; Samuelson, Lars; Solid State Physics/the Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund, Sweden; Westervelt, Robert M; Department of Physics, Harvard University, Cambridge, MA 02138, USA ; School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
Журнал:
Nanotechnology
Дата:
2011-05-06
Аннотация:
We use a scanning gate microscope (SGM) to characterize one-dimensional ultra-thin (diameter≈30 nm) InAs/InP heterostructure nanowires containing a nominally 300 nm long InAs quantum dot defined by two InP tunnel barriers. Measurements of Coulomb blockade conductance versus backgate voltage with no tip present are difficult to decipher. Using the SGM tip as a charged movable gate, we are able to identify three quantum dots along the nanowire: the grown-in quantum dot and an additional quantum dot near each metal lead. The SGM conductance images are used to disentangle information about individual quantum dots and then to characterize each quantum dot using spatially resolved energy-level spectroscopy.
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