Understanding a Bisferrocene Molecular QCA Wire - Field-Coupled Nanocomputing: Paradigms, Progress, and Perspectives - page 333

Fig. 36 (E), mainly localized near the molecule, with low values of equivalent
voltage.
In summary, this analysis reveals that the tolerance of the QCA wire to some
possible defects in the fabrication of the QCA wire is quite good. In addition, the
results obtained and the data highlighted in Fig. 36 give an important feedback
to the technologist about which are the critical points and which could be the
improvement to assure a correct information propagation.
4 Conclusions
We summarized the most important characteristics of molecules currently under
study as potential candidates as QCA devices. In particular we focused and
discussed our method aimed at solving one of the gap that is preventing those
molecules from being exhaustively studied from an electronic point of view and
used as elements in a circuit. We indeed presented our two stages methodol-
ogy, which starts from ab-initio simulations in several conditions followed by a
second stage where post-processing is executed and electrostatic inspections are
performed. The outcome is twofold. First, we improved the understanding of a
MQCA wire based on a bis-ferrocene molecule and assess the conditions under
which it can be used as well as the constraints the technological process should
be subjected to. Second, we proposed a method to systematically and thoroughly
study this and other molecules to be used as perspective MQCA devices. Though
several steps are still necessary, our contribution enables the study of MQCA
with an electronic perspective, allowing then to move from the single device
level to a circuit level, still maintaining a strong link with the technological
aspects.
References
1. Lent, C.S., Tougaw, P.D., Porod, W., Bernstein, G.H.: Quantum cellular automata.
Nanotechnology 4 , 49-57 (1993)
2. Vankamamidi, V., Ottavi, M., Lombardi, F.: Clocking and cell placement for QCA.
In: IEEE-NANO 2006, vol. 1, pp. 343-346 (2006)
3. Graziano, M., Vacca, M., Chiolerio, A., Zamboni, M.: A NCL-HDL Snake-Clock
based magnetic QCA architecture. IEEE Trans. Nanatechnol. 10 (5), 1141-1149
(2011)
4. Graziano, M., Chiolerio, A., Zamboni, M.: A technology aware magnetic QCA
NCL-HDL architecture. In: 9th IEEE Conference on Nanotechnology, 2009, IEEE-
NANO 2009, Genova, Italy, pp. 763-766. IEEE (2009)
5. Hennessy, K., Lent, C.S.: Clocking of molecular quantum-dot cellular automata.
J. Vac. Sci. Technol. B 19 , 1752-1755 (2001)
6. Lent, C.S., Isaksen, B.: Clocked molecular quantum-dot cellular automata. IEEE
Trans. Electron Devices 50 , 1890-1896 (2003)
7. Lent, C.S., Isaksen, B., Lieberman, M.: Molecular quantum-dot cellular automata.
J. Am. Chem. Soc. 125 , 1056-1063 (2003)