Fig. 3: Current-phase relation at zero temperature.
From: Effect of dilute impurities on short graphene Josephson junctions
Here, the impurity density is set at \({n}_{{{{{{\rm{imp}}}}}}}{t}_{0}^{2}/{{{\Delta }}}_{0}^{2}=0.1\). Panels a and b show the supercurrent as a function of the phase ϕ in units of \({I}_{{{{{{\rm{c}}}}}}}^{* }=e{{{\Delta }}}_{0}W/(\hslash L)\), and the Fermi energy is set at μ0 = 0 and μ0 = 5ħvD/L, respectively. In both panels one has γ → 0+ (black dashed lines) γ = 10−2Δ0 (yellow solid lines), γ = 10−1Δ0 (red solid lines), γ = Δ0 (green solid lines), γ = 10Δ0 (blue solid lines), γ → ∞ (cyan dashed lines, i.e. the clean limit). The dotted gray vertical line denotes ϕ*, which is the superconductive phase difference such that \(I({\phi }^{* })=\mathop{\max }\limits_{\phi }I(\phi )\) in the clean GJJ, in particular ϕ* = 0.63π for μ0 = 0, and ϕ* = 0.68π for μ0 = 5ħvD/L. Panels c and d show supercurrent I(ϕ*) (red solid line), at zero temperature, as a function of γ, and the Fermi energy is set at μ0 = 0 and μ0 = 5ħvD/L, respectively. In panels c and d, the horizontal lines refer to two limiting cases: I(ϕ*), at zero temperature, in the clean limit (horizontal cyan dashed line) and in the presence of single-energy impurities (horizontal black dashed line), i.e. γ → 0+.
