Landauer current and mutual information

We study quantum evolution of the mutual information of a quantum dot connected to left and right leads initially maintained at chemical potentials μL and μR, respectively, within the noninteracting resonant-level model. The full nonequilirbium mixed state density matrix of the whole system is written down exactly, and the mutual information of the dot with respect to the leads is computed. A strong and direct correlation is found between the Landauer current and the mutual information at all times, the steady-state values in particular displaying a quadratic relationship at high temperatures. Strikingly, it is found that one can obtain a maximal mutual information by simply applying a sufficiently large "source-drain" voltage VSD even at high temperatures.