caa a22 4500 463212630 CHVBK 20180405153146.0 cr unu---uuuuu 170326e20071101xx s 000 0 eng 10.1007/s00339-007-4187-2 doi (NATIONALLICENCE)springer-10.1007/s00339-007-4187-2 Graphene-based superconducting quantum point contacts [Elektronische Daten] [A.G. Moghaddam, M. Zareyan] We investigate the Josephson effect in the graphene nanoribbons of length L smaller than the superconducting coherence length and an arbitrary width W. We find that in contrast to an ordinary superconducting quantum point contact (SQPC), the critical supercurrent Ic is not quantized for the nanoribbons with smooth and armchair edges. For a low concentration of the carriers, Ic decreases monotonically with lowering W/L and tends to a constant minimum for a narrow nanoribbon with $W\lesssim{}L$ . The minimum Ic is zero for the smooth edges but $e\Delta_{0}/\hbar$ for the armchair edges. At higher concentrations of the carriers this monotonic variation acquires a series of peaks. Further analysis of the current-phase relation and the Josephson coupling strength IcRN in terms of W/L and the concentration of carriers revels significant differences with those of an ordinary SQPC. On the other hand for a zigzag nanoribbon, we find that, similar to an ordinary SQPC, Ic is quantized but to the half-integer values $(n+1/2)4e\Delta_{0}/\hbar$ . Springer-Verlag, 2007 Moghaddam A.G. Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, 45195, Zanjan, Iran aut Zareyan M. Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, 45195, Zanjan, Iran aut Applied Physics A Springer-Verlag 89/3(2007-11-01), 579-585 0947-8396 89:3<579 2007 89 339 https://doi.org/10.1007/s00339-007-4187-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00339-007-4187-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Moghaddam A.G. Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, 45195, Zanjan, Iran aut NATIONALLICENCE 700 1- Zareyan M. Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45195-1159, 45195, Zanjan, Iran aut NATIONALLICENCE 773 0- Applied Physics A Springer-Verlag 89/3(2007-11-01), 579-585 0947-8396 89:3<579 2007 89 339 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer