Bi-stable tunneling current through a molecular quantum dot
Abstract
An exact solution is presented for tunneling through a negative-U d-fold degenerate molecular quantum dot weakly coupled to electrical leads. The tunnel current exhibits hysteresis if the level degeneracy of the negative-U dot is larger than two (d>2). Switching occurs in the voltage range V1 < V < V2 as a result of attractive electron correlations in the molecule, which open up a new conducting channel when the voltage is above the threshold bias voltage V2. Once this current has been established, the extra channel remains open as the voltage is reduced down to the lower threshold voltage V1. Possible realizations of the bi-stable molecular quantum dots are fullerenes, especially C60, and mixed-valence compounds.
Cite
@article{arxiv.cond-mat/0204387,
title = {Bi-stable tunneling current through a molecular quantum dot},
author = {A. S. Alexandrov and A. M. Bratkovsky and R. S. Williams},
journal= {arXiv preprint arXiv:cond-mat/0204387},
year = {2009}
}
Comments
5 pages, 1 figure. (v2) Figure updated to compare the current hysteresis for degeneracies d=4 and d>>1 of the level in the dot, minor corrections in the text. To appear in Phys. Rev. B