First-principles study of electron transport through $C_{20}$ cages

Electron transport properties of C${}_{20}$ molecules suspended between gold electrodes are investigated using first-principles calculations. Our study reveals that the conductances are quite sensitive to the number of C${}_{20}$ molecules between electrodes: the conductances of C${}_{20}$ monomers are near 1 G${}_0$, while those of dimers are markedly smaller, since incident electrons easily pass the C${}_{20}$ molecules and are predominantly scattered at the C${}_{20}$-C${}_{20}$ junctions. Moreover, we find both channel currents locally circulating the outermost carbon atoms.