Low Temperature Physics: 42, 924 (2016); https://doi.org/10.1063/1.4965893
Физика Низких Температур: Том 42, Выпуск 10 (Октябрь 2016), c. 1177-1183    ( к оглавлению , назад )

Fluctuation conductivity due to the preformed local pairs

T. Domański

Institute of Physics, M. Curie Skłodowska University, 20–031 Lublin, Poland
E-mail: doman@kft.umcs.lublin.pl

M. Barańska

Institute of Physics, Polish Academy of Sciences, 02–668 Warsaw, Poland

A.L. Solovjov

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Pr. Nauky, Kharkiv 61103, Ukraine

Received May 21, 2016


We investigated the properties of a system where the itinerant electrons coexist and interact with the preformed local pairs. Using the nonperturbative continuous unitary transformation technique we show that Andreev-type scattering between these charge carriers gives rise to the enhanced diamagnetic response and is accompanied by appearance of the Drude peak inside the pseudogap regime ω ≤ 2Δpg. Both effects are caused by the short-range superconducting correlations above the transition temperature Tc. In fact, the residual diamagnetism has been detected by the torque magnetometry in the lanthanum and bismuth cuprate superconductors at temperatures up to ~ 1.5Tc. In this work we show how the superconducting correlations can be observed in the ac and dc conductivity.

PACS: 74.25.N– Response to electromagnetic fields;
PACS: 72.10.–d Theory of electronic transport; scattering mechanisms;
PACS: 05.10.Cc Renormalization group methods;
PACS: 71.10.Li Excited states and pairing interactions in model systems.

Key words: cuprate superconductors, preformed pairs, short-range correlations, Drude peak.

Published online: August 29, 2016