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We derive expressions for the superfluid density ρs in the low-temperature limit T → 0 in dwave superconductors, taking into account the presence of competing orders such as spin-density waves, idxy-pairing, etc. Recent experimental data for the thermal conductivity and for elastic neutron scattering in La2−xSrxCuO4 suggest there are magnetic field induced anomalies that can be interpreted in terms of competing orders. We consider the implications of these results for the superfluid density and show in the case of competing spin-density wave order that the usual Voloviklike √ H depletion of ρs(H) is replaced by a slower dependence on applied magnetic field. We find that it is crucial to include the competing order parameter in the self-consistent equation for the impurity scattering rate.

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“…It was shown Ref. [17] that for the superfluid density this approximation works reasonably well at low temperatures.…”

Section: Introductionmentioning

confidence: 88%

“…The validity of the Doppler-shift approximation was discussed in Refs. [16,17] using the quasiclassical Eilenberger equations. It was shown Ref.…”

Section: Introductionmentioning

confidence: 99%

Superfluid density and competing orders ind-wave superconductors

Sharapov

Ćarbotte

2006

Phys. Rev. B

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“…where α depends on the symmetry of the gap and on impurities [98], and in clean cases α = 1 or α = 1 2 in fully gapped superconductors and in superconductors with lines of nodes, respectively. More accurate treatments [99,100] do not change the qualitative result of a significant reduction of the superfluid density with the application of a magnetic field.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Mixed-State Microwave Response in Superconducting Cuprates

et al. 2006

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We investigate the physics of the microwave response in YBa 2 Cu 3 O 7−δ , SmBa 2 Cu 3 O 7−δ and MgB 2 in the vortex state. We first recall the theoretical basics of vortex-state microwave response in the London limit. We then present a wide set of measurements of the field, temperature, and frequency dependences of the vortex state microwave complex resistivity in superconducting thin films, measured by a resonant cavity and by sweptfrequency Corbino disk. The combination of these techniques allows for a comprehensive description of the microwave response in the vortex state in these innovative superconductors. In all materials investigated we show that flux motion alone cannot take into account all the observed experimental features, neither in the frequency nor in the field dependence. The discrepancy can be resolved by considering the (usually neglected) contribution of quasiparticles to the response in the vortex state. The peculiar, albeit different, physics of the superconducting materials here considered, namely two-band superconductivity in MgB 2 and superconducting gap with lines of nodes in cuprates, give rise to a substantially increased contribution of quasiparticles to the field-dependent microwave response. With careful combined analysis of the data it is possible to extract or infer many interesting quantities related to the vortex state, such as the temperature-dependent characteristic vortex frequency and vortex viscosity, the field dependence of the quasiparticle density, the temperature dependence of the σ-band superfluid density in MgB 2

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Electrical resistance and magnetic properties of double-doped ceramics La1.85−4∕3xSr0.15+4∕3xCu1−xMnxO4

Tkach

Пономарев

Charikova

et al. 2007

Low Temperature Physics

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Resistive and magnetic measurements are made on La1.85−4∕3xSr0.15+4∕3xCu1−xMnxO4 ceramics with x=0.02, 0.04, 0.06, and 0.08. It is found that at these concentrations the temperature of the beginning and end of the superconducting transition depend weakly on the concentration x. The resistive properties exhibit a combination of metallic conductivity (or superconductivity) along the grains with hopping transport between grains. At low temperatures the superconductivity apparently coexists with two different magnetic phases.

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Magnetic-field-drivenx≈1/8anomaly of superconductivity inLa2−x−y

Cited by 3 publications

References 26 publications

Superfluid density and competing orders ind-wave superconductors

Superfluid density and competing orders ind-wave superconductors

Mixed-State Microwave Response in Superconducting Cuprates

Electrical resistance and magnetic properties of double-doped ceramics La1.85−4∕3xSr0.15+4∕3xCu1−xMnxO4

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