Superconductivity : systems, properties, and theories / editor, Raymond M. Cortez.

Format:

Book

Contributor:

Cortez, Raymond M.

Series:

Superconductivity Research and Applications

Language:

English

Subjects (All):

Superconductivity.

Superconductors.

Physical Description:

1 online resource (438 p.)

Edition:

1st ed.

Place of Publication:

Hauppauge, N.Y. : Nova Science Publishers, c2011.

Language Note:

English

Summary:

This book presents and discusses research in the study of superconductivity. Topics discussed herein include applications of confined quantum field theory to condensed matter systems; thermodynamic properties of superconducting states; vortices in layered superconductors; superconductivity in highly correlated systems; combined effects of disorder and magnetic field in superconductors; and the critical currents and vortex dynamics in percolative superconductors.

Contents:

Intro

SUPERCONDUCTIVITY SYSTEMS, PROPERTIES AND THEORIES

CONTENTS

PREFACE

Chapter1APPLICATIONSOFCONFINEDQUANTUMFIELDTHEORYTOCONDENSEDMATTERSYSTEMS:SUPERCONDUCTINGPHASETRANSITIONSINFILMS,WIRESANDGRAINS

Abstract

1.Introduction:PhaseTransitionsinConfinedSystems

2.SuperconductingTransitioninFilms

2.1.TheEffectivePotentialfortheGLModelwithOneCompactifiedDimen-sion

2.2.MassRenormalizationandTransitionTemperature

2.3.EffectoftheCoupling-ConstantCorrectiononTc(L)

3.SuperconductingTransitionTemperatureinWiresandGrains

3.1.Compactificationofad-dimensionalSubspace

3.2.CriticalBehaviorforWires

3.3.CriticalBehaviorforGrains

4.CriticalBehaviorofType-IISuperconductingFilmsinaMagneticField

4.1.Coupling-ConstantCorrectioninthePresenceofanExternalMagneticField

4.2.TheGapEquationandtheCriticalCurve

5.ConcludingRemarks

Acknowledgements

References

Chapter2THERMODYNAMICPROPERTIESOFSUPERCONDUCTINGSTATESUNDERMAGNETICFIELDS

1.Introduction

2.QuasiclassicalEquations

2.1.DerivationofQuasiclassicalEquations

2.2.CasesofSingletandUnitaryTripletPairingsandGeneratingFunctionalofQuasiclassicalTheory

3.ApproximateAnalyticSolution

3.1.BPTApproximation

3.2.Self-consistentEquationsforRenormalizationFactors, (n)(i!n)and (a)(i!n)

3.3.ThermodynamicQuantities

3.4.ExtensiontoMultibandSuperconductors

4.ComparisonwithNumericalResults

5.FieldAngleDependence

5.1.EffectofGapAnisotropy

5.2.EffectofFermiVelocityAnisotropy

6.Conclusion

Acknowledgments

A.CircleProduct

B.PropertiesofFaddeevaFunction

Chapter3STRONG-COUPLINGTHEORYOFHIGHTEMPERATURESUPERCONDUCTIVITY

Introduction

1.BandStructureandEssentialInteractionsinCuprates

2."Fr¨ohlich-Coulomb"ModelofHTS

2.1.SingleLatticePolaron.

2.2.Non-adiabaticSmallPolaron

2.3.AdiabaticSmallPolaron

2.4."1/ "ExpansionTechnique:PolaronBand

2.5.FromContinuoustoSmallHolsteinandSmallFr¨ohlichPolarons:QMCSimulation

2.6.AttractiveCorrelationsofSmallPolarons

3.SuperlightBipolaronsinHigh-TcCuprates

3.1.ApexBipolarons

3.2.In-planeBipolarons

3.3.Low-Energy(Bi)PolaronEnergyStructureofCuprates

3.4.RoleofDisorderandthePhaseDiagramofCuprates

3.5.LowFermiEnergy:IndividualPairinginCuprates

4.NormalStatePropertiesofCupratesinFCM

4.1.NormalStateIn-planeResistivity,theHallEffect,MagneticSusceptibilityandtheLorenzNumber

4.2.Normal-StateNernstEffect

4.3.NormalStateDiamagnetism

4.4.SpinPseudogap,c-axisTransportandChargePseudogap

5.SuperconductingStateofCuprates

5.1.Parameter-FreeEvaluationofTc:Bose-EinsteinCondensationversustheKosterlitz-ThoulessTransition

5.2.IsotopeEffectonTcandonSupercarrierMass

5.3.SpecificHeatAnomaly

5.4.UniversalUpperCriticalField

5.5.SymmetryandSpaceModulationsoftheOrderParameter

6.OverdopedCuprates:Boson-FermionMixtures

6.1.MobileFermionsHybridisedwithImmobileBosons:Boson-FermionModel

6.2.AbsenceofBCS-BECCrossoverinBFM

6.3.NormalandAnomalousGreen'sFunctionsof3DBFM: Pairingof Bosons

6.4.Gor'kovExpansion

7.Conclusion

Chapter 4 VORTICES IN LAYERED SUPERCONDUCTORS

1. Introduction

1.1. General

1.2. Dimensionality and Vortices

2. Theory

2.1. The Lawrence-Doniach Model

2.1.1. Josephson Vortex (at or near ab plane)

2.1.2. Pancake Vortex (at or near c-axis)

2.1.3. Kinked and Tilted Vortices

2.1.4. Vortex Lattice and Combine Vortices

2.2. Types of Vortices, Angular Regimes and Intrinsic Pinning

2.3. Lock-in Transition and Vortex Structure

2.4. The Anisotropic Ginzburg-Landau Limit

2.5. Dimensionality

2.6. Vortex Lock-in Scenario.

3. Vortex Mapping Techniques

3.1. Scanning

3.2. Flux Flow Resistivity

4. Experimental Observations of Vortices

4.1. Scanning

4.2. Flux Flow Resistivity

4.2.1. Vortex Types

4.2.1.1. Pancake Vortex Regime

4.2.1.2. Tilted Vortex Regime

4.2.1.3. Combine and Josephson Vortex Regimes

4.2.1.4. Four-Types of Vortices and their Phase Diagrams

4.2.1.4.1. The -t Phase Diagram

4.2.1.4.2. The -H Phase Diagram

4.2.1.5. Lock-in Transition Theories

4.2.1.5.1. Theoretical Fits to the -t and -H Data

4.2.1.5.2. Remarks

4.3. Irreversibility Line versus Lock-in Transition

4.3.1. Irreversibility Field Lines

4.3.2. Lock-in Transition

4.3.3. The Correlation

4.4. Dimensionality and Lock-in Transition

5. Pertinent Issues

5.1. Pairing Symmetry

5.2. Consequences of d-wave Pairing Symmetry

5.3. Coherence Length

Conclusion

Acknowledgment

Chapter 5 HARMONIC COMPONENTS OF THE VOLTAGE ON THE SURFACE OF SUPERCONDUCTING SLABS AND CYLINDERS BELOW AND ABOVE THE CRITICAL CURRENT

2. Experimental

3. Superconducting Slab in Parallel Applied Magnetic Field

4. Superconducting Cylinder with Axial Current below the Critical Current

5. Superconducting Cylinder with Applied Axial Current above the Critical Current

6. Inclusion of the Resistive Voltage

Conclusions

Appendix

Chapter 6 SUPERCONDUCTIVITY IN HIGHLY CORRELATED SYSTEMS

Superconductivity from Repulsion

2. Factors Governing Pairing Symmetry and TC Dimensionality and Fermiology

2.1. Singlet vs Triplet Pairings in 2D vs 3D

2.2. Why is TC so Low? Higher TC in "Disconnected Fermi Surfaces

2.3. Better the Nesting, the Better?

3. Spin- vs Charge-Fluctuation Mediated Pairing

4. Time-Reversal-Broken vs Non-Unitary Superconductivity.

5. Crossover between the Hubbard Model and the Electron Gas

6. High TC System vs Fractional Quantum Hall System

7. Concluding Remarks

Chapter 7 SUPERCONDUCTING FLUCTUATIONS ABOVE TC IN OVERDOPED BI2SR2CACU2O8+δ

3. Results and Discussion

4. Conclusion

Chapter8ELECTRICNOISEANDLOCALPHOTON-INDUCEDNONEQUILIBRIUMSTATESINACURRENT-CARRYINGNANOSTRUCTUREDSUPERCONDUCTOR

2.ThinFilmandNanostructuringTechnology

2.1.DepositionofNbandNbNThinFilms

2.2.NanopatterningofNbandNbNThinFilms

3.CharacterizationofSuperconductingFilms andNanostructures

3.1.SuperconductingTransitionTemperatureofFilms

3.2.SecondCriticalMagneticFieldofFilms

3.3.SuperconductingTransitionTemperatureofBridges

3.4.CriticalCurrentDensityofBridges

4.Current-AssistedHot-SpotPhotonDetection

4.1.ModelRefinement

4.2.FluctuationsandQuantumEfficiencybeyondtheCut-off

5.Single-PhotonDetectorCharacterization

5.1.ExperimentalSetup

5.2.DarkCountsandFluctuations

5.3.SpectralDetectionEfficiency

6.Summary

Chapter 9 VORTEX ENTRY CONDITIONS IN TYPE-II SUPERCONDUCTORS: GIBBS-LONDON APPROACH VS GINZBURG-LANDAU THEORY

2. Geometrical Barrier, a Single-Vortex Approach

3. Vortex-Entry Condition: Ginzburg-Landau Theory

1. General Equations

2. Vortex Entry Condition - Numerical Study

3. Vortex Entry Criterion: Numerical Results vs London Theory

4. Vortex Entry Criterion - Analytical Study

5. Vortex Exit

6. Thin Film

4. Summary

Chapter 10 SUPERCONDUCTIVITY AND MAGNETISM IN THE RUTHENO-CUPRATES -RUR2-XCEXSR2CU2O10-δ (RU-1222) AND RUSR2RCU2O8 (RU-1212, R=EU AND GD)

1. Basic Concepts.

1.1. Crystal Structures and X-rays Data

1.2. The Ru Valence State in Ru-1212 and Ru-1222

2. Superconductivity in Ru-1222 and Ru-1212 and Results and Model

2.1. SC in the RuR2-xCexSr2Cu2O10-δ System

A Simple Model for SC in Ru-1222

2.2. SC in the RuSr2RCu2O8 System

2.3. Substitutions in Ru-1222 System

2.4. Substitutions in Ru-1212 System

2.5. Physical Properties of the SC State

2.6. The Granular Behavior of the SC State

3. The Magnetic State in RuSr2R2-xCexCu2O10-δ Results and Model

3.1. The Magnetic Properties of RuY1.5Ce0.5Sr2Cu2O10 (Ru -1222Y)

3.2. The Qualitative Magnetic Structure of (Ru -1222Y)

3.3. Decoupling of the Two SC and Magnetic States

3.4. The Magnetic Properties of RuEu2-xCexSr2Cu2O10-δ System

3.5. The Major W-FM Magnetic Region

3.6. Mössbauer Effect and μSR Studies

3.7. The Minor AFM Magnetic Region

3.8. The Sr-Ru-Cu-O3 System

3.9. Anisotropic Magnetization of RuEu1.5Ce0.5Sr2Cu2O10 Thin Films

4. Summary and Conclusions

4.1. Proposed Models for Magnetic States of Ceramics RuEu2-xCex Sr2Cu2O10-δ

Chapter11COMBINEDEFFECTSOFDISORDERANDMAGNETICFIELDINSUPERCONDUCTORS

2.EffectsofanExternalMagneticField

2.1.MeissnerEffectandMixedPhase

2.2.Bogoliubov-deGennesEquations

2.3.VortexStates

2.3.1.Caroli,deGennesandMatriconStates

2.3.2.VortexCharge

2.4.HighFieldRegime

2.5.Quasiparticle-VortexScattering

2.5.1.FranzandTesanovicGaugeTransformation

2.6.DOS,LDOSandSTMMeasurements

2.7.HallConductance.ThoulessTheorem

2.8.SpinHallConductance

3.EffectsofDisorderandMagneticField

3.1.HighFieldLandauRegime:ImpurityDisorder

3.2.HighFieldLandauRegime:VortexDisorder

3.3.RandomVorticesinLowtoIntermediateFields

3.4.CombinedEffectsofImpuritiesandPinning.

3.5.EffectsofDisorderontheVortexCharge.

Notes:

Description based upon print version of record.

Includes bibliographical references and index.

Description based on print version record.

ISBN:

1-61209-051-6

OCLC:

831625480