The Kosterlitz-Thouless transition in 2D superconductors: open problems and new perspectives

by Dr Lara Benfatto (CNR-ISC)

Friday 5 Mar 2010, 11:00 → 12:00 Europe/Rome

Aula Corbino (Dip. di Fisica - Edificio E. Fermi)

Seminario Organizzato da CNR-ISC In the last years a renewed interest emerged on the occurrence of the Kosterlitz-Thouless (KT) transition in quasi two-dimensional (2D) systems like cuprate superconductors, films of conventional superconductors, or the two-dimensional electron gas created at the interface between oxides in artificial heterostructures. All these systems have shown that KT physics can occur with characteristics that appear somehow 'unconventional' with respect to the properties emerged in the study of superconducting thin films in the 80's. However, despite the appearences, several anomalies can be reconciled with the conventional KT transition once that new ingredients are taken into account, like the crucial role played by vortex-core energy or the intrinsic inhomogeneity of the system. In this talk I will review some of our results, and I will discuss their relevance in the context of new emerging syste! ms where they have been successfully applied. L. Benfatto, C. Castellani and T. Giamarchi, Phys. Rev. Lett. 98, 117008 (2007); Phys. Rev. Lett. 99, 207002 (2007); Phys. Rev. B 77, 100506(R) (2008); Phys. Rev. B 80, 214506 (2009).