Abstract:
We present first principles simulations of whole elongation process of different metallic (Al, Au, Pd) nanocontacts [1] studied using fast local basis set DFT Fireball [2] code combined with the Keldysh Green's function approach for electronic transport. At variance with all the previous theoretical works, presented approach provides direct access to a realistic structure for the nanocontact [3]. This key ingredient is not directly accessible to the experiments and all the previous theoretical attempts with ideal geometries (single atom or short atomic chains) have failed to reproduce basic experimental features. We also discuss the process of the formation of gold monoatomic chains and the role of impurities (H,O) on the whole process and their influence on transport properties. The results are compared to experimental measurements [4].

References:
[1] N. Agrait et al. Phys. Rep. 377, 81-279 (2003)
[2] http://www.physics.byu.edu/research/lewis/fireball/index.htm
[3] P.Jelinek et al. Phys. Rev. B 68, 085403(2003)
[4] Sz. Csonka et al. Phys. Rev. Lett. 90, 116803 (2003)