The surface barrier in mesoscopic type I and type II superconductors

Abstract

We study the surface barrier for magnetic field penetration in mesoscopic samples of both type I and type II superconductors. Our results are obtained from numerical simulations of the time-dependent Ginzburg-Landau equations. We calculate the dependence of the first field for flux penetration ($H_p$) with the Ginzburg-Landau parameter ($\kappa$) observing an increase of $H_p$ with decreasing $\kappa$ for a superconductor-insulator boundary condition ($(\nabla -iA)\Psi {|}_n=0$) while for a superconductor-normal boundary condition (approximated by the limiting case of $\Psi {|}_S=0$) $H_p$ has a smaller value independent of $\kappa$ and proportional to $H_c$. We study the magnetization curves and penetration fields at different sample sizes and for square and thin film geometries. For small mesoscopic samples we study the peaks and discontinuous jumps found in the magnetization as a function of magnetic field. To interpret these jumps we consider that vortices located inside the sample induce a reinforcement of the surface barrier at fields greater than the first penetration field $H_{p1}$. This leads to multiple penetration fields $H_{pi}=H_{p1},H_{p2},H_{p3},...$ for vortex entrance in mesoscopic samples. We study the dependence with sample size of the penetration fields $H_{pi}$. We explain these multiple penetration fields extending the usual Bean-Livingston analysis by considering the effect of vortices inside the superconductor and the finite size of the sample.

12 pages, 11 figures. Revised version. Section III rewritten. Some figures changed

Cited by in corpus (15)

• Dynamics of vortex penetration, jumpwise instabilities and nonlinear surface resistance of type-II superconductors in strong rf fields
• Neutron Stars in the Laboratory
• Predicted field-dependent increase of critical currents in asymmetric superconducting nanocircuits
• Time-dependent Ginzburg-Landau treatment of RF Magnetic Vortices in Superconductors: Vortex-Semiloops in a Spatially Nonuniform Magnetic Field
• Dark photon vortex formation and dynamics
• Effects of thermal fluctuations on the magnetic behavior of mesoscopic superconductors
• Impact of border defects on the magnetic flux penetration in superconducting films
• Variational approach to vortex penetration and vortex interaction
• The ac magnetic response of mesoscopic type II superconductors
• Structured light and induced vorticity in superconductors I: Linearly polarized light
• Vortex dynamics induced by scanning SQUID susceptometry
• Paramagnetic excited vortex states in superconductors
• Enhancement of penetration field in vortex nanocrystals due to Andreev bound states
• Dissipation in Mesoscopic Superconductors with Ac Magnetic Fields
• Vortex-driven superconducting diode effect in asymmetric multilayer heterostructures