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arXiv · 0706.2240

Vibration-mediated resonant tunneling and shot noise through a molecular quantum dot

X. Y. Shen·Bing Dong·X. L. Lei·N. J. M. Horing
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Abstract

Motivated by a recent experiment on nonlinear tunneling in a suspended Carbon nanotube connected to two normal electrodes [S. Sapmaz, {\it et al}., Phys. Rev. Lett. {\bf 96}, 26801 (2006)], we investigate nonequilibrium vibration-mediated sequential tunneling through a molecular quantum dot with two electronic orbitals asymmetrically coupled to two electrodes and strongly interacting with an internal vibrational mode, which is itself weakly coupled to a dissipative phonon bath. For this purpose, we establish rate equations using a generic quantum Langevin equation approach. Based on these equations, we study in detail the current-voltage characteristics and zero-frequency shot noise, paying special attention to the advanced or postponed of the appearance of negative differential conductance and super-Poissonian current noise resulting from electron-phonon-coupling induced {\em selective unidirectional cascades of single-electron transitions}.

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X. Y. Shen, Bing Dong, X. L. Lei, N. J. M. Horing. 2007-06-15. Vibration-mediated resonant tunneling and shot noise through a molecular quantum dot. https://doi.org/10.1103/physrevb.76.115308

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