Pseudogap and local pairs in high-Tc cuprate superconductors

Solovjov, A. L.; Tkachenko, M. A.

doi:10.48550/arxiv.1112.3812

Cited by 4 publications

(17 citation statements)

References 29 publications

(102 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As was convincingly shown (see Ref. [9,54,65,66] and references therein), near T c , σ ′ (T ) is always extrapolated by the standard equation of the Aslamasov-Larkin (AL) theory [67] with the critical exponent λ = −1/2 which determines FLC in any three-dimensional (3D) system,…”

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 88%

“…But the proper mechanism of LP pairing still remains unknown. At T pair << T * SBBs transform into fluctuating Cooper pairs (FCPs) [22,23,32,58], thus demonstrating the BEC-BCS transition [9,54] predicted by the theory [50][51][52][53]. This is a specific property of the HTSCs, which is the consequence of the extremely short coherence length in cuprates [2,3,9,10,50].…”

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 97%

“…Hence, the excess conductivity σ ′ (T ), which appears as a result of the PG opening, has to contain information about the pseudogap. To get the information, a special approach based on the local-pair (LP) model has been developed [9,54]. In accordance with the model, the PG is believed to appear due to the LPs formation at T ≤ T * , accordingly regarded as a pseudogap temperature.…”

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 99%

“…σ ′ (T ), found with a help of Eq. ( 1) for all five aforementioned samples, has been analyzed within the LP model [9,54] paying more attention to the possible difference of the revealed results in comparison with those obtained for YPrBCO (sample L100) [47] and YBCO (sample F1) [63] films regarded as reference objects. Importantly, all studied samples have been treated in the identical way.…”

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 99%

“…In this case, the significant reduction of T c is followed by nonmetallic resistivity temperature dependence [47]. Obviously, to be analyzed in terms of the LP model [9,[50][51][52][53][54] only samples with metallic ρ(T ), like the aforesaid SLs and SDs, have been studied.…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Specific temperature dependence of pseudogap in YBa2Cu3O7−δ nanolayers

et al. 2016

Self Cite

View full text Add to dashboard Cite

The pseudogap (PG) derived from the analysis of the excess conductivity σ ′ (T ) in superlattices and double-layer films of YBa2Cu3O 7−δ − PrBa2Cu3O 7−δ (YBCO-PrBCO), prepared by pulsed laser deposition, is studied for the first time. The σ ′ (T ) analysis has been performed within the local-pair (LP) model based on the assumption of the paired fermion (LPs) formation in the cuprate highTc superconductors (cuprates) below the representative temperature T * ≫ Tc resulting in the PG opening. Within the model, the temperature dependencies of the PG, ∆ * (T ), for the samples with different number of the PrBCO layers (NP r ) were analyzed in the whole temperature range from T * down to Tc. Near Tc, σ ′ (T ) was found to be perfectly described by the Aslamasov-Larkin (AL) and Hikami-Larkin (HL) [Maki-Thompson (MT) term] fluctuation theories, suggesting the presence of superconducting fluctuations in a relatively large (up to 15 K) temperature range above Tc. All sample parameters were found to change with increase of NP r , finally resulting in the appearance of the pronounced maximum of ∆ * (T ) at high temperatures. The result is most likely due to increasing influence of the intrinsic magnetism of PrBCO (µP r ≈ 4 µB) and suggests the possibility to search in that way the change of interplay between the superconductivity and magnetism in cuprates.

show abstract

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 88%

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 97%

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 99%

Section: Results and Discussion A Fluctuation Conductivitymentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Specific temperature dependence of pseudogap in YBa2Cu3O7−δ nanolayers

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

Hydrostatic-pressure effects on the pseudogap in slightly doped YBa2Cu3O7−δ single crystals

Solovjov

Omelchenko

Вовк

et al. 2016

Physica B: Condensed Matter

View full text Add to dashboard Cite

The influence of hydrostatic pressure up to P=1.05 GPa on resistivity, excess conductivity σ ′ (T ) and pseudogap ∆ * (T ) is investigated in slightly doped single crystals of Y Ba2Cu3O 7−δ (Tc(P = 0) ≈49.2 K and δ ≈ 0.5). The critical temperature Tc is found to increase with increasing pressure at a rate dTc/dP = +5.1 KGP a −1 , while ρ(300) K decreases at a rate dlnρ/dP = (−19±0.2)% GP a −1 . Near Tc, independently on pressure, the σ ′ (T ) is well described by the Aslamasov-Larkin and HikamiLarkin fluctuation theories, demonstrating a 3D-2D crossover with increase of temperature. The crossover temperature T0 determines the coherence length along the c-axis ξc(0) ≃ (3.43 ± 0.01)Å at P=0, which is found to decrease with increasing P. At the same time, ∆ * and the BCS ratio 2∆ * /kB Tc both increase with increasing hydrostatic pressure at a rate dln∆ * /dP ≈ 0.36 GP a −1 , implying an increase of the coupling strength with increasing P. At low temperatures below Tpair, the shape of the ∆ * (T ) curve is found to be almost independent on pressure. At high temperatures, the shape of the ∆ * (T ) curve changes noticeably with increasing P, suggesting a strong influence of pressure on the lattice dynamics. This unusual behavior is observed for the first time.

show abstract