Pseudogap effects in strongly correlated electron systems

Boyarsky, Leonid A.

doi:10.1063/1.2219503

Cited by 7 publications

(3 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results of the numerical modeling of these phenomena [158] based on phenomenological representation of the free energy of the system as a function of two interacting order parameters, superconducting and non-superconducting, indicate their possible connection with a certain ordering (probably, that of charge density waves) that competes with superconductivity. According to this widely discussed hypothesis in the literature (see, e.g., reviews [143,144,157]), the latter also determines the appearance of the pseudo-gap. In the above phase diagram (Fig.…”

Section: Energy 'Pseudo-gap' As An Independent Phase Transition In Himentioning

confidence: 99%

“…lose the connection between them [144], or that a pseudo-gap at above the superconducting transition temperature appears due to the influence of clusters of superparamagnetic or antiferromagnetic ordering as a kind of 'magnetic glue' which occurs when a high-temperature superconductor is not doped or poorly doped with charge carriers [145]. It is also thought that such a mechanism lies in the formation of spin-or charge-density standing waves involving magnetically ordered structures of indirect exchange via the conduction electrons in their organization, leading to the formation of virtual quasi-localized states, but other ideas exist as well [143][144][145][146][147][148].…”

Section: Fig 14 Comparison Of Critical Superconducting Transition Tmentioning

confidence: 99%

“…At the same time, using different experimental techniques [139,140] it was recorded that there is another energy gap emerging at a temperature above the critical, which was called as a 'phony' gap or a 'pseudo-gap' because of its inexplicable origin [30,[137][138][139][140][141][142][143]. A number of researchers explain its appearance with the phase transition to a special 'pseudo-gap' state, and various hypotheses of the phenomena occurring during this process are considered in the proposed models.…”

Section: Fig 14 Comparison Of Critical Superconducting Transition Tmentioning

confidence: 99%

See 2 more Smart Citations

High-temperature superconductivity: From macro- to nanoscale structures

Коваленко¹

2016

Nanosystems: Phys. Chem. Math.

View full text Add to dashboard Cite

The analysis of achievements, problems and prospects of high-temperature superconductivity (HTSC) in the macro-and nanostructured materials has been given. The main experimental results and theoretical models describing the physical mechanisms of the superconductivity appearance at phenomenological and microscopic levels, including change in the energy spectrum of atoms in these materials with the advent of the 'superconducting' gap at temperatures below the critical transition, as well as the above-critical temperature 'pseudo-gap' have been analyzed.Although the origin of the pseudo-gap is not completely understood, it can be considered as an independent phase transition in the substance prior to the transition to the zero resistance state and insusceptibility (or insensitivity) to external magnetic field in high-temperature superconductors. Features of multi-gap and gapless superconducting materials as well as their ability to further increase the temperature of supercritical transition are discussed. Large resources to create the necessary electron and phonon spectra in the process of high-temperature superconductivity formation are associated with the use of nanoscale structures and nanoparticles of conductors and dielectrics. Electrical conductive contacts between nanoparticles and tunnel chains of nanoclusters, where delocalized electron spectra form similar energy shells to the atomic or nuclear shells, play a significant part here. It is required to further investigate the occurrence of high-temperature superconductivity at the level of interphase layers (non-autonomous phases) in nanostructures containing a large fraction of the substance in this condition. It is essential to develop adequate methods for synthesis of nanoparticles of variable size, structure and morphology, as well as techniques for their consolidation that would ensure the preservation of superconductivity of individual nanoparticles, their chemical, thermal, magnetic and current stability in the dissipative processes with functional and fluctuation effects.

show abstract

Section: Energy 'Pseudo-gap' As An Independent Phase Transition In Himentioning

confidence: 99%

Section: Fig 14 Comparison Of Critical Superconducting Transition Tmentioning

confidence: 99%

Section: Fig 14 Comparison Of Critical Superconducting Transition Tmentioning

confidence: 99%

See 1 more Smart Citation

High-temperature superconductivity: From macro- to nanoscale structures

Коваленко¹

2016

Nanosystems: Phys. Chem. Math.

View full text Add to dashboard Cite

show abstract

Preparation of CdBa2Cu3O7−δ superconducting ceramic and a study of its electrical properties

Aliev

Ragimov

et al. 2011

Low Temperature Physics

View full text Add to dashboard Cite

A new superconducting ceramic material CdBa2Cu3O7−δ is obtained. It is found that the superconducting transition (at 86 K) is retained when yttrium is fully replaced by cadmium in the Y-Ba-Cu-O system. X-ray diffraction studies show that the crystalline structure is unchanged and the identified peaks coincide when Y is replaced by Cd in YBa2Cu3O7−δ. Besides a stable superconducting transition, a phase transition near 275 K was seen in the temperature dependence of the specific resistivity which shifted toward lower temperatures (252 K) and then disappeared completely over repeated measurement cycles. The thermal conductivity k of YBa2Cu3O7−δ and CdBa2Cu3O7−δ was found to vary little with temperature up to the superconducting transition. Substituting Cd for Y in the initial HTSC material led to a substantial increase in the lattice thermal conductivity. Measurements of the thermal emf showed that it is positive in YBa2Cu3O7−δ and negative in CdBa2Cu3O7−δ.

show abstract

Pseudogap in CdBa2Cu3O7−δ HTSC material

Aliev

Ragimov

Селим-заде

2013

Low Temperature Physics

View full text Add to dashboard Cite

Long-lived minima are detected at Tmin1 = 275 K and Tmin2 = 252 K in the ρ(T) curve of polycrystalline CdBa2Cu3O7−δ, which has a superconducting transition at 86.8 K. It is shown that the excess conductivity Δσ(T) near Tmin obeys the classical Aslamazov-Larkin fluctuation theory. This suggests that fluctuation Cooper pairs may develop in CdBa2Cu3O7−δ at T ≫ Tc. The experimental data are used to calculate the coherence length ξc(0), the 2D-3D crossover temperature T0, and the interplanar pairing constants. The magnitude and temperature dependence of the pseudogap for a sample without the minima are found to be typical of cuprate HTSC materials.

show abstract

Pseudogap effects in strongly correlated electron systems

Abstract: An analytical survey of pseudogap effects in the electron spectra of strongly correlated systems is presented. The relationship of these effects with the Friedel virtual levels model is discussed.

Cited by 7 publications

References 16 publications

High-temperature superconductivity: From macro- to nanoscale structures

High-temperature superconductivity: From macro- to nanoscale structures

Preparation of CdBa2Cu3O7−δ superconducting ceramic and a study of its electrical properties

Pseudogap in CdBa2Cu3O7−δ HTSC material

Contact Info

Product

Resources

About