Transport through a molecular quantum dot in the polaron crossover regime

Alex Zazunov (1, 2, 3) , Thierry Martin (1, 3)

1 CPT - Centre de Physique Théorique - UMR 6207
2 LPM2C - Laboratoire de physique et modélisation des milieux condensés
3 CPT - Centre de Physique Théorique - UMR 7332

We consider resonant transport through a molecular quantum dot coupled to a local vibration mode. Applying the non-equilibrium Green function technique in the polaron representation, we develop a non-perturbative scheme to calculate the electron spectral function of the molecule in the regime of intermediate electron-phonon coupling. With increasing tunneling coupling to the leads, correlations between polaron clouds become more important at relatively high temperature leading to a strong sharpening of the peak structure in the spectral function. The detection of such features in the current-voltage characteristics is briefly discussed.

Mots clés: Molecular electronics; Keldysh formalism; polaron; electron-phonon interaction; phonon sidebands; spectral function; greens function

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Alex Zazunov, Thierry Martin. Transport through a molecular quantum dot in the polaron crossover regime. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 76 (3), pp.033417. ⟨hal-00138198⟩