Critical current density and vortex phase diagram in the superconductor Sn0.55In0.45Te

Critical current density and vortex pinning dynamics have been studied in the superconductor Sn0.55In0.45Te. Analysis of the temperature-dependent lower critical field shows that it has a weakly anisotropic single energy gap. The critical current density Jc(0) and pinning potential U0(H) values reach as high as 2.56??103 A/cm2 at 1.8 K and 2.1??103 K at ??0H = 0.01 T, respectively. Based on the collective pinning model, we demonstrate the coexistence of vortex pinning regimes in Sn0.55In0.45Te. One is a ??Tc pinning regime induced by the spatial fluctuations of the transition temperature in a low field. The other is a dominantly ??l pinning regime associated with the spatial variations of the charge-carrier mean free path in a higher field. This causes a nonconstant exponent of the power-law behavior Jc(T ) ??? Hn. A very weak vortex fluctuation is unveiled by a narrow separation between the irreversibility field ??0Hirr(T ) and upper critical field ??0Hc2(T ) in the vortex phase diagram. We discuss the potential application in superconducting electronics like the single-photon detector in thin film form.

Automated summary

The critical current density and vortex pinning dynamics in the superconductor Sn0.55In0.45Te have been investigated. The analysis of the temperature-dependent lower critical field reveals a weakly anisotropic single energy gap. The high values of critical current density Jc(0) and pinning potential U0(H) were observed at different conditions. Based on the collective pinning model, the coexistence of two vortex pinning regimes in Sn0.55In0.45Te was confirmed, one induced by the spatial fluctuations of the transition temperature and the other associated with the spatial variations of the charge-carrier mean free path.