Naslov
Localized superconductivity in insulating TiN thin films

Autori
A. Bilusic, T. I. Baturina, A. Yu. Mironov, V. M. Vinokur, M. R. Baklanov, M. V. Fistul, C. Strunk

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Moriond 2008: Quantum Transport and Nanophysics , La Thuile, Italija, 08.-15.03.2008. / - , 2008

Skup
Moriond 2008: Quantum Transport and Nanophysics

Mjesto i datum
La Thuile, Italija, 08.03.2008. - 15.03.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
superconductor-insulator transition; Josephson junctions; Coulomb blockade

Sažetak
We present an investigation of low-temperature transport properties of TiN thin films being in the critical region of the superconductor- insulator transition (SIT), driven by the level of film disorder. At very low temperatures, insulating films exhibit zero-conductance state. It can be destroyed by magnetic field, and by an applied bias voltage greater than some well defined threshold value. The threshold bias voltage is magnetic-field dependent. Magnetoresistance of films from both sides of the SIT is huge and positive for low, and negative for high fields. Exceptions are films being deeper on the insulating side of the SIT critical region, which exhibit positive magnetoresistance for all fields. At elevated temperatures the resistivity of insulating films is thermally activated, with magnetic-field dependent activation energy. The appearance of the threshold voltage and the activation energy in insulating films, together with their magnetic field dependence, is explained as a survival of the superconducting phase in the form of weakly Josephson coupled and strongly Coulomb-blockaded islands. Thus the transport of Cooper pair is highly correlated, resulting in a renormalized and size dependent charging energy.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA