Ballistic conductance calculation of atomic-scale nanowires of Au and Co

Abstract

Ballistic conductance calculations on infinite one-atom zigzag chains of Co and Au, and multi-atom Au nanowires, were computed using the Landauer–Büttiker formalism within the local-density approximation (LDA). In the cobalt case, the majority spin channel exhibits quantized conductance, but because of the close spacing of the d levels, the minority channel does not. The calculated conductance is somewhat larger than what is observed. We suggest that the discrepancy is an indication that the Landauer–Büttiker formalism breaks down in this narrow d band material. In contrast, Au (which was determined not to be spin polarized) does show well-behaved quantization in the case of the infinite zigzag chain. By increasing the dimension of the cross section of the chain, we find that quantization is lost once the lateral dimensions of the wire exceed two or so atoms. Finally, we show that the zigzag chain of Au can have a Peierls instability, making the chain insulating.

Electronic structure effects on stability and quantum conductance in 2D gold nanowires

“…The electronic contribution to the conductance behavior has not been investigated in detail except for the linear nanowire. 8,9,13,36 In this section, we present correlation between electronic structure and conductance behavior of 2D For linear NW, the transmission at the Fermi level shows a jump from 3G o to 1G o as shown in Fig. 5(a), in agreement with, the earlier reports on conductance calculations.…”

The increase in conductance of a gold single atom chain during elastic elongation

“…Gold SACs also have great potential in applied fields such as nanoelectronics. Many experimental [1][2][3][4][5][6][7][8][9][10] and theoretical [11][12][13][14][15][16][17][18][19][20][21][22][23][24] studies have been carried out to explain the SAC formation and its electrical characteristics. Using density-functional theory (DFT) simulations, it was found that during the nanowire elongation, the arrangement of the gold atoms changes from three-dimensional (3D) phases to a variety of two-dimensional (2D) phases and finally to SACs, which elongate gradually from one up to about nine atoms in the chain.…”

The effect of internal impurities on the mechanical and conductance properties of gold nanowires during elongation

“…To verify this interpretation, many theoretical studies have been published to explain the structural changes that occur during gold NW elongation and determine the effect of these configurations on the conductance [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. Indeed, it was found that during the elongation, the arrangement of the gold atoms changes from three-dimensional (3D) phases to a variety of two-dimensional (2D) phases and finally to SACs, which elongate gradually from one up to about nine atoms in the chain.…”