Even-odd oscillation of conductance of 5{it d} metal atomic nanowires

The electron-transport properties of single-row monoatomic nanowires made of 5$d$ elements are examined by first-principles calculations based on the density functional theory. We found that oscillation patterns with a period longer than two-atom length are dominant in the conductance of Ir and Pt monoatomic nanowires, although the transmission of the $s$-$d_{z^2}$ channel still exhibits even-odd oscillatory behavior. When the nanowires are deformed into zigzag configurations from the straight configuration, the oscillation behavior of the patterns with long periods changes and the oscillations eventually disappear. On the other hand, the even-odd oscillatory behavior of the $s$-$d_{z^2}$ channel still survives even in the deformed nanowire. The even-odd oscillation in the conductance of Ir and Pt nanowires is interpreted to be due to the low sensitivity of the oscillation of the $s$-$d_{z^2}$ channel to the spatial deformation of the nanowires.