Comment on 'Hysteresis, Switching, and Negative Differential Resistance in Molecular Junctions: a Polaron Model', by M. Galperin, M.A. Ratner, and A. Nitzan, Nano Lett. 5, 125 (2005)
| dc.creator | Alexandrov, A. S. | |
| dc.creator | Bratkovsky, A. M. | |
| dc.date | 2006-03-17 | |
| dc.date | 2006-04-10 | |
| dc.date.accessioned | 2026-07-07T07:04:48Z | |
| dc.date.available | 2026-07-07T07:04:48Z | |
| dc.description | It is shown that the ``hysteresis'' in a polaron model of electron transport through the molecule found by M.Galperin et al. [Nano Lett. 5, 125 (2005)] is an artefact of their ``mean-field'' approximation. The reason is trivial: after illegitimate replacement $\hat{n}^{2}=\hat{n}n_{0},$ where \hat{n} is the electron number operator, n_{0} the average molecular level occupation, Galperin et al. obtained non-physical dependence of a renormalized molecular energy level on the non-integer mean occupation number n_{0} (i.e. the electron self-interaction) and the resulting non-linearity of current. The exact theory of correlated polaronic transport through molecular quantum dots (MQDs) that we proposed earlier [Phys. Rev. B67, 235312 (2003)] proved that there is no hysteresis or switching in current-voltage characteristics of non-degenerate, d=1, or double degenerate, d=2, molecular bridges, contrary to the mean-field result. Switching could only appear in multiply degenerate MQDs with d>2 due to electron correlations. Most of the molecular quantum dots are in the regime of weak coupling to the electrodes addressed in our formalism. | |
| dc.description | 3 pages, no figures; (v3) estimates added showing that most of the molecules are very resistive, so the actual molecular quantum dots are in the regime we study, unlike very transparent `molecules' studied by Galperin et al and other authors. In the latter case the molecules are rather `transparent' and, obviously, no current hysteresis can exist | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0603467 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0603467 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/109450 | |
| dc.subject | Materials Science | |
| dc.subject | Soft Condensed Matter | |
| dc.title | Comment on 'Hysteresis, Switching, and Negative Differential Resistance in Molecular Junctions: a Polaron Model', by M. Galperin, M.A. Ratner, and A. Nitzan, Nano Lett. 5, 125 (2005) | |
| dc.type | text |