First-Principles Theory of Correlated Transport through Nanojunctions

We report the inclusion of electron-electron correlation in the calculation of transport properties within an ab initio scheme. A key step is the reformulation of Landauer’s approach in terms of an effective transmittance for the interacting electron system. We apply this framework to analyze the effect of short-range interactions on Pt atomic wires and discuss the coherent and incoherent correction to the mean-field approach.

Figure 1

(a) System layout divided in the leads and conductor regions. Open (full) circles are uncorrelated (correlated) Pt atoms. (b) Band structure of the Pt infinite chain. $A$ is the edge of the one-dimensional Brillouin zone. (c) Transmittance of the noninteracting conductor region. The inset shows the isosurface plot of a computed MLWF.

Figure 2

Curves: Spectral function projected on the interacting region (left) and effective transmittance (right) for the case of three correlated atoms in the Pt chain. Shaded areas: mean-field reference results. (a),(b) The results obtained with the total correlation SE ${\Sigma }_{\mathrm{corr}}={\Sigma }_{3\mathrm{BS}}$. The (c),(d) [(e),(f)] plots are obtained using only the Hermitian [anti-Hermitian] SE ${\Sigma }_H$ [${\Sigma }_A$].

Figure 3

(a) Effective transmittance against energy for variable number of correlated atoms in the chain: $A$ is the reference mean-field bulk transmittance. $N_C=1$, 3, 5, 7 in B, C, D, E. (b) Effective transmittance for a Au-Pt-Au junction (three Pt atoms). Solid lines: mean-field description of an infinite Au chain (thin line) and of the Au-Pt-Au interface (thick line). Shaded area: interface treatment including correlation.