Ivan A. Pshenichnyuk » charge transport https://pshenichnyuk.ru Fri, 12 Jul 2024 10:02:39 +0000 en hourly 1 http://wordpress.org/?v=3.1 LaTeX test https://pshenichnyuk.ru/?p=48 https://pshenichnyuk.ru/?p=48#comments Sat, 05 Mar 2011 20:53:21 +0000 Ivan http://pshenichnyuk.ru/?p=48 Despite its simplicity, the model is very important from theoretical point of view. It’s analytically solvable in both scattering and ME approaches and provides a basis for discussion and comparison. The atom of impurity plays a role of the molecular bridge, which contains one electronic level with energy \varepsilon_0, available for tunneling, and no internal degrees of freedom. Changing the notation of the basis vector |n=0\rangle to |d\rangle, bridge’s Hamiltonian reads

H_s = |d\rangle \varepsilon_0 \langle d| .

Leads, as always in this work, are presented by two half-infinite tight binding chains (HITBC). Their Hamiltonian in k-representation reads

H_l = \sum\limits_{k\alpha} |k\alpha\rangle \varepsilon_{k\alpha} \langle k\alpha| ,

where \alpha=l,r is used to distinguish left and right lead. Chemical potential \mu_{\alpha} is in general different for different leads. When we speak about a voltage U, applied to the junction, we assume \mu_l=+\frac{V}{2} and \mu_r=-\frac{V}{2}.

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