Gradual decrease of conductance of an adiabatic ballistic constriction below 2e2/h
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
70
Journal Issue
19
Pages
1-5
Date Issued
2004
Author(s)
Abstract
We have performed four-terminal conductance measurements of a one-dimensional (1D) channel in which it is possible to modulate the potential profile using three overlaying finger gates. In such a 1D ballistic structure we have observed that the conductance steps show a gradual decrease from 2e 2/h to 0.97 x 2e2/h with increasing negative finger gate voltage in a short, clean 1D constriction. We suggest this phenomenon is due to differing shifts of 1D subbands with changing split-gate voltage. Both a simple analytical estimate for an adiabatic constriction and a realistic modeling of the device give the same magnitude of the conductance decrease as observed in our experiments.
Type
journal article