Effects of Structural Relaxation on Conductance Oscillations in Atomic Chains
Abstract
Many theoretical studies have been devoted to electrical properties of short atomic chains. One of the interesting features revealed by them is that the conductance of Na chains depends on the number of atoms being even or odd. This parity oscillation was suggested to be a universal feature of atomic chains. In contrast, a recent calculation reported that the conductance of Al chains would oscillate in a period of four atoms, instead of two. Since most of theoretical studies focusing on the parity oscillation assumed fixed atomic positions in the chains, we perform ab initio force calculation to consider relaxation effects on Na atomic chains between two electrodes using the boundarymatching scatteringstate density functional method developed by our group. We have found that the oscillatory behavior of the conductance is much reduced after structural relaxation. From the current density distribution, it is seen that the reflection in the stable chain is much reduced than that in the initial geometry. Our results suggest that the conductance of relaxed Na chains may tend to be close to the ideal value of quantized conductance.
 Publication:

APS March Meeting Abstracts
 Pub Date:
 March 2004
 Bibcode:
 2004APS..MAR.C1160H