Spatially resolved manipulation of single electrons in quantum dots using a scanned probe.
The scanning metallic tip of a scanning force microscope was coupled capacitively to electrons confined in a lithographically defined gate-tunable quantum dot at a temperature of 300 mK. Single electrons were made to hop on or off the dot by moving the tip or by changing the tip bias voltage owing to the Coulomb-blockade effect. Spatial images of conductance resonances map the interaction potential between the tip and individual electronic quantum dot states. Under certain conditions this interaction is found to contain a tip-voltage induced and a tip-voltage-independent contribution.
Pioda
A
A
Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland.
Kicin
S
S
Ihn
T
T
Sigrist
M
M
Fuhrer
A
A
Ensslin
K
K
Weichselbaum
A
A
Ulloa
S E
SE
Reinwald
M
M
Wegscheider
W
W