Graphene based superconducting quantum point contacts

dc.creatorMoghaddam, Ali G.
dc.creatorZareyan, Malek
dc.date2008-06-23
dc.date.accessioned2026-07-07T09:46:08Z
dc.date.available2026-07-07T09:46:08Z
dc.descriptionWe 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 $I_c$ is not quantized for the nanoribbons with smooth and armchair edges. For a low concentration of the carriers $I_c$ decreases monotonically with lowering $W/L$ and tends to a constant minimum for a narrow nanoribbon with $W\lesssim L$. The minimum $I_c$ is zero for the smooth edges but $eΔ_{0}/\hbar$ 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 $I_cR_N$ 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, $I_c$ is quantized but to the half-integer values $(n+1/2)4eΔ_{0}/\hbar$.
dc.description8 pages, 5 figures
dc.identifierhttps://arxiv.org/abs/0806.3625
dc.identifierhttp://arxiv.org/abs/0806.3625
dc.identifierAppl. Phys. A 89, 579-585 (2007)
dc.identifierdoi:10.1007/s00339-007-4187-2
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/163425
dc.subjectMesoscale and Nanoscale Physics
dc.subjectSuperconductivity
dc.titleGraphene based superconducting quantum point contacts
dc.typetext

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