Landauer Current and Mutual Information

Abstract

We study quantum evolution of the entanglement of a quantum dot connected to left and right leads initially maintained at chemical potentials $\mu_{L}$ and $\mu_{R}$ respectively, within the non-interacting resonant-level model. The full nonequilirbium mixed state density matrix of the whole system is written down exactly, and entanglement is computed by recourse to the notion of mutual information. A strong and direct correlation is found between the Landauer current, and the entanglement 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 maximally entangled quantum dot by simply applying a sufficiently large `source-drain' voltage $V_{SD}$ even at high temperatures.