Influence of contacts on the conductivity of thin wires

The conductivity of thin wires was shown to depend noticeably on the properties and, particularly, dimensionality of contacts. Two- and one-dimensional contacts create a strongly nonuniform electric field in a wire which, in turn, causes the redistribution of electron density along a wire and nonlinear current-voltage characteristic. The particular shape of the latter has been calculated for both Ohmic and Schottky contacts of different dimensionality. The case of ac applied voltage is also considered. Spatial distribution of nonequilibrium carriers is found for different signal frequencies omega. The wire conductivity is shown to increase with omega for any type of low-dimensional contacts. (C) 1998 American Institute of Physics. [S0021-8979(98)08923-3]