Valerii Vinokour, Argonne National Laboratory, USA

Jeudi 22 Decembre, 16h
Amphi Howleck, Esc C, 1ème etage

Superinsulator-Superconductor Duality : Experiment and Theory

Valerii Vinokour
Argonne National Laboratory, USA

By fine-tuning disorder, the ultrathin superconducting film (with the thickness less than the superconducting coherence length) can be transformed from superconductor to insulator. We discuss the vortex binding-unbinding Berezinskii-Kosterlitz-Thouless (BKT) transition at the superconducting side, where the high-temperature resistive state of the film turns into a phase-coherent superconducting state. We find a dual charge-binding-unbinding BKT transition at the insulating side. The observed low-temperature phase of the charge-BKT transition is the strongly correlated superinsulating state, which at very lowest temperatures terminates the Cooper pair insulator with the activated type conductivity. We discuss the fundamental aspect of the superinsulation-superconductivity duality in the framework of Heisenberg uncertainty principle. On the microscopic level, considering the charge transfer in two-dimensional Josephson junction arrays, we observe that the tunneling current in their insulating state is ensured by the relaxation mediated by the Cooper pairs dipole environment. The energy gap, appearing in the Cooper pairs dipole spectrum below the BKT transition, gives rise to suppression of the tunneling current offering the microscopic mechanism for the superinsulating behavior.


Haut de page



À lire aussi...

Rick Greene, Center for Nanophysics & Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA

Jeudi 15 Septembre 2011, 16h00Amphi Howleck, Esc C, 2ème etage Link between spin fluctuations and Cooper pairing in copper oxide superconductors (...) 

> Lire la suite...

Khashayar Khazen, University of Nottingham INSP

Jeudi 22 Septembre 2011,16hAmphi Howleck, Esc C, 1ème etage Current Status and perspective of ferromagnetic semiconductors : GaMnAs and beyond (...) 

> Lire la suite...