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Quantum Transport

AG von Oppen

To the problem of definition of the transition temperature in 2D superconductor

Location: Fachbereich Physik, FB-RaumTime: Wednesday 27.02.2008, 11h c.t. |

First of all I will discuss the specifics of fluctuations in 2D superconductor and possible ways of the critical temperature definition. Then I will concentrate on the method based on calculation of the renormalized superfluid density in frameworks of both BKT and GL schemes. For comparison I will show how GL and BKT fluctuations renormalize the critical current of Josephson junction beyond Ambegaokar-Baratoff theory. The modulus and phase fluctuation corrections will be considered in the Ginzburg-Landau approximation, but in the immediate vicinity of the critical temperature, when the value of the critical current itself becomes small, all orders of perturbation theory will be collected. Finally small vortex-antivortex fluctuations in superconducting phase below the region of critical fluctuations and their role in matching of BKT and GL schemes will be discussed.

**More information:** F. von Oppen (vonoppenphysik.fu-berlin.de)

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