2014/07/23 by Ionut-Dragos Potirniche, Joseph Maciejko, Rahul Nandkishore +1 · 1 citation
Materials Science · Physics and Astronomy · #Condensed matter physics #Dirac (video compression format) #Dirac fermion #Fermion #Graphene #Graphene research and applications #Physics #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #Topological Materials and Phenomena #cond-mat.dis-nn #cond-mat.mes-hall #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.90.094516
published as Phys. Rev. B 90, 094516 (2014) · Updated references
arxiv created 2014/07/23 · openalex publication_date 2014/09/24 · arxiv updated 2014/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We numerically study the interplay between superconductivity and disorder on the graphene honeycomb lattice with on-site Hubbard attractive interactions U using a spatially inhomogeneous self-consistent Bogoliubov--de Gennes (BdG) approach. In the absence of disorder there are two phases at charge neutrality. Below a critical value Uc for attractive interactions there is a Dirac semimetal phase and above it there is a superconducting phase. We add scalar potential disorder to the system, while remaining at charge neutrality on average. Numerical solution of the BdG equations suggests that while in the strong attraction regime (U>Uc) disorder has the usual effect of suppressing superconductivity, in the weak attraction regime (U<Uc) weak disorder enhances superconductivity. In the weak attraction regime, disorder that is too strong eventually suppresses superconductivity, i.e., there is an optimal disorder strength that maximizes the critical temperature Tc. Our numerical results also suggest that in the weakly disordered regime, mesoscopic inhomogeneities enhance superconductivity significantly more than what is predicted by a spatially uniform mean-field theory in the manner of Abrikosov and Gorkov. In this regime, superconductivity consists of rare phase-coherent superconducting islands. We also study the enhancement of the superconducting proximity effect by disorder and mesoscopic inhomogeneities, and obtain typical spatial plots of the tunneling density of states and the superfluid susceptibility that can be directly compared to scanning tunneling microscopy experiments on proximity-induced superconductivity in graphene.