Oscillatory Nonlinear Conductance of an Interacting Quantum Wire with an Impurity

The nonlinear conductance of a one-dimensional quantum wire adiabatically coupled to Fermi liquid electron reservoirs is determined in the presence of an impurity. We show that electron-electron interaction in connection with the finite length of the wire leads to characteristic oscillations in the current as a function of the applied voltage.

Figure 1

The backscattered current $I_{\mathrm{B}\mathrm{S}}$ is depicted, in units of $e(\lambda {\omega }_L^g/{\omega }_c^g{)}^2/{\omega }_L$, as a function of $u=eU/{\omega }_L$. The interaction strength is $g=0.25$. The solid line corresponds to ${\xi }_0=0$ and the dashed line to ${\xi }_0=0.25$. Decaying oscillations with a constant period are clearly visible for the case ${\xi }_0=0$.

Figure 2

The backscattered current $I_{\mathrm{B}\mathrm{S}}$ is plotted, in units of $I_{\mathrm{B}\mathrm{S}}^{\mathrm{s}\mathrm{t}}$, as a function of $u=eU/{\omega }_L$ for three different values of the interaction strength: $g=0.25$ (dotted line), $g=0.50$ (dashed line), and $g=0.75$ (solid line). Electron-electron interaction affects the decay as well as the phase shift of the oscillations.