Looking for the Origin of Power Laws in Electric Field Assisted Tunneling

H. Cabrera[1], D.A. Zanin[1], L.G. De Pietro[1], A. Vindigni[1], U. Ramsperger[1], D. Pescia[1]
[1]Laboratory for Solid State Physics, ETH Zurich, Zurich, Switzerland
Veröffentlicht in 2013

A sharp tip approached perpendicular to a conducting surface at subnanometer distances and biased with a small voltage builds a junction across which electrons can be transferred from the tip apex to the nearest surface atom by direct quantum mechanical tunneling. Such a junction is used e.g. in Scanning Tunneling Microscopy (STM). When the distance d between tip and collector is increased beyond some nanometers, the junction enters the electric field assisted regime, the one underlying the topografiner technology –an imaging technique widely used in micro- and nano-electronics. Recent experiments in this regime suggest a scaling law which can be tested numerically by verifying the collapsing of a family of electric potential curves, computed at different d, onto one single curve.