DC voltage profile of a 1D pumped wire with an impurity

FEDERICO FOIERI, LILIANA ARRACHEA , MARÍA JOSÉ SÁNCHEZ

PHYSICA B - CONDENSED MATTER

ELSEVIER SCIENCE BV

Año: 2009 vol. 404 p. 2802 - 2806

0921-4526

In this work we study the behavior of the voltage profile of a 1D quantum wire with an impurity when transport is induced by two ac voltages that oscillating with a phase lag define a quantum pump. Thevoltage profile sensed along the wire by the voltage probe, that we assume weakly coupled to the system, exhibits a Friedel’s oscillations structure inside the region delimited by the position of the twoac voltages that induce transport. On the other hand, outside this region the oscillations are suppressed.Using perturbation theory in the coupling constant of the voltage probe we derived analytical expressions for the DC current valid for the adiabatic regime. We also compare our analytical resultswith the exact numerical calculations using Keldysh non-equilibrium Green’s functions formalism.