Temperature-independent pseudogap and thermally activated c-axis hopping conductivity in layered cuprate superconductors
| Autor: | U. T. Kurbanov, O.K. Ganiev, E.X. Karimboev, S. Dzhumanov, Sh.S. Djumanov |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Doping Conductivity Condensed Matter Physics Polaron Electrical resistivity and conductivity Condensed Matter::Superconductivity Pairing Condensed Matter::Strongly Correlated Electrons General Materials Science Cuprate Electrical and Electronic Engineering Pseudogap |
| Zdroj: | Superlattices and Microstructures. 68:6-15 |
| ISSN: | 0749-6036 |
| Popis: | The carrier localization (confinement) and c -axis charge transport in high- T c layered cuprates have been investigated in the temperature-independent pseudogap state over a wide doping range from the underdoped to the overdoped regime, focusing on the nanoscale phase separation into two different domains (i.e. carrier-rich CuO 2 layers and carrier-poor regions between the CuO 2 layers) caused by inherent nanoscale electronic inhomogeneities and on the real-space pairing of polaronic carriers caused by strong electron–phonon interactions in carrier-poor regions. A simple microscopic model for layered cuprate superconductors is proposed to describe the carrier confinement and formation of localized bipolarons in the low-doping regions between the CuO 2 layers and to simulate the c -axis hopping transport at the thermal dissociation of such bipolarons. This model is found to describe properly the c -axis charge transport, which is governed by thermally activated hopping of polarons residing in the localized state between the CuO 2 layers due to the existence of the temperature-independent bipolaronic pseudogap, and the insulating behavior of the c -axis resistivity ρ c ( T ) observed above T c in various cuprate superconductors, from the underdoped to the overdoped regime. It is found that the insulating behavior of ρ c ( T ) is changed to metallic behavior with disappearing of bipolaronic pseudogap. |
| Databáze: | OpenAIRE |
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