Superconductor-insulator transition in two dimensions

Abstract

The superconductor-insulator transition of ultrathin films of bismuth, grown on liquid-helium-cooled substrates, has been studied. The transition was tuned by changing both film thickness and perpendicular magnetic field. Assuming that the transition is controlled by a Tϭ0 critical point, a finite-size scaling analysis was carried out to determine the correlation length exponent and the dynamical critical exponent z. The phase diagram and the critical resistance have been studied as a function of film thickness and magnetic field. The results are discussed in terms of bosonic models of the superconductor-insulator transition, as well as the percolation models which predict finite dissipation at Tϭ0.

Granular electronic systems

“…One can see that there exists a critical value of the normal state resistance R 0 close to the value of quantum resistance h/(2e) 2 ≈ 6.4k Ω such that samples with resistance R < R 0 eventually become superconducting under temperature decrease, while those with R > R 0 show tendency to the insulating behavior. Such a behavior turned out to be generic and was observed in a number of granular (as well as on homogeneously disordered, (Frydman et al, 2002;Liu et al, 1993;Marković et al, 1999)) films made from different materials.…”

Electronically driven superconductor-insulator transition in electrostatically doped La2CuO4+δthin films

“…29 In Figs. 8b and 8c we show the results of this analysis for the 9 T and 0 T transitions respectively.…”

Zero-bias anomaly in homogeneously disordered MoGe nanowires undergoing a superconductor-insulator transition

“…In superconducting films close to the critical point, the low-bias resistance isotherms follow the finite size scaling model 4,5,16,17 , which gives strong indication that the SIT in films is also a quantum phase transition (QPT). In addition, it has been shown that in amorphous MoGe 5 and NbN 17 films, nonlinear differential resistance measured as a function of magnetic field at several finite bias voltages also scales both on the insulating and superconducting sides of the SIT.…”

“…It is now well established that a discontinuous superconductor-insulator transition (SIT) takes place in several disordered two-dimensional superconducting film systems 1,2,3,4,5,6 . Rather unexpectedly, recent experiments indicate that a direct SIT can also occur in long one-dimensional superconducting nanowires 7,8 .…”