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How backscattering off a point impurity can enhance the current and make the conductance greater than e^2/h per channel

D. E. Feldman·Yuval Gefen
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Abstract

It is well known that while forward scattering has no effect on the conductance of one-dimensional systems, backscattering off a static impurity suppresses the current. We study the effect of a time-dependent point impurity on the conductance of a one-channel quantum wire. At strong repulsive interaction (Luttinger liquid parameter g<1/2), backscattering renders the linear conductance greater than its value e^2/h in the absence of the impurity. A possible experimental realization of our model is a constricted quantum wire or a constricted Hall bar at fractional filling factors nu=1/(2n+1) with a time-dependent voltage at the constriction.

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D. E. Feldman, Yuval Gefen. 2002-07-25. How backscattering off a point impurity can enhance the current and make the conductance greater than e^2/h per channel. https://doi.org/10.1103/physrevb.67.115337

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