Phenomenological model for the third-harmonic magnetic response of superconductors: application to SrRuO
arXiv:2105.01813 · doi:10.1103/PhysRevB.104.064502
Abstract
We employ the phenomenological Lawrence-Doniach model to compute the contributions of the superconducting fluctuations to the third-harmonic magnetic response, denoted here by , which can be measured in a precise way using ac magnetic fields and lock-in techniques. We show that, in an intermediate temperature regime, this quantity behaves as the third-order nonlinear susceptibility, which shows a power-law dependence with the reduced temperature as . Very close to , however, saturates due to the nonzero amplitude of the ac field. We compare our theoretical results with experimental data for three conventional superconductors -- lead, niobium, and vanadium -- and for the unconventional superconductor SrRuO (SRO). We find good agreement between theory and experiment for the elemental superconductors, although the theoretical values for the critical field systematically deviate from the experimental ones. In the case of SRO, however, the phenomenological model completely fails to describe the data, as the third-harmonic response remains sizable over a much wider reduced temperature range compared to Pb, Nb, and V. We show that an inhomogeneous distribution of can partially account for this discrepancy, since regions with a locally higher contribute to the fluctuation significantly more than regions with the "nominal" of the clean system. However, the exponential temperature dependence of first reported in Ref. [3] is not captured by the model with inhomogeneity. We conclude that, while inhomogeneity is an important ingredient to understand the superconducting fluctuations of SRO and other perovskite superconductors, additional effects may be at play, such as non-Gaussian fluctuations or rare-region effects.
arXiv comment13 pages, 10 figures
References in corpus (43)
- Time-Reversal Symmetry Breaking Superconductivity in Sr2RuO4
- The Nernst effect in high- superconductors
- High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
- Vanishing of phase coherence in underdoped Bi_2Sr_2CaCu_2O_8+d
- Pronounced drop of O NMR Knight shift in superconducting state of SrRuO
- Strong Peak in of SrRuO Under Uniaxial Pressure
- Diamagnetism and Cooper pairing above in cuprates
- Chiral P-Wave Order in Sr_2RuO_4
- Gaussian superconducting fluctuations, thermal transport, and the Nernst effect
- Nernst effect in metals and superconductors: a review of concepts and experiments
- Temporal correlations of superconductivity above the transition temperature in LaSrCuO probed by terahertz spectroscopy
- Split superconducting and time-reversal symmetry-breaking transitions, and magnetic order in SrRuO under uniaxial stress
- Giant superconducting fluctuations in the compensated semimetal FeSe at the BCS-BEC crossover
- A proposal for reconciling diverse experiments on the superconducting state in Sr2RuO4
- Stabilizing Even-Parity Chiral Superconductivity in SrRuO
- High Field Studies of Superconducting Fluctuations in High-T_c Cuprates: Evidence for a Small Gap distinct from the Large Pseudogap
- Knight Shift and Leading Superconducting Instability From Spin Fluctuations in Sr2RuO4
- Decrease of upper critical field with underdoping in cuprate superconductors
- Temperature range of superconducting fluctuations above T_c in YBa_2Cu_3O_{7-δ} single crystals
- Evidence for even parity unconventional superconductivity in SrRuO
- Giant Nernst Effect due to Fluctuating Cooper Pairs in Superconductors
- Emergence of superconductivity in the cuprates via a universal percolation process
- Nernst effect and disorder in the normal state of high-T_{c} cuprates
- Superconducting order parameter of SrRuO: a microscopic perspective
- Inhomogeneous time-reversal symmetry breaking in
- Fluctuoscopy of Disordered Two-Dimensional Superconductors
- Fluctuations of the superconducting order parameter as an origin of the Nernst effect
- Micron-scale measurements of low anisotropic strain response of local in SrRuO
- Thermodynamics of Gaussian fluctuations and paraconductivity in layered superconductors
- Confinement of superconducting fluctuations due to emergent electronic inhomogeneities
- Superconducting order of from a three-dimensional microscopic model
- Angular dependence of the upper critical field of Sr2RuO4
- Dynamical Conductivity Across The Disorder-Tuned Superconductor-Insulator Transition
- Thermodynamic transitions in inhomogeneous d-wave superconductors
- Nernst effect in the electron-doped cuprate superconductor PCCO: Superconducting fluctuations, upper critical field Hc2, and the origin of the Tc dome
- Global critical temperature in inhomogeneous superconductors induced by multifractality
- Percolative nature of the dc paraconductivity in the cuprate superconductors
- Dislocations and the enhancement of superconductivity in odd-parity superconductor SrRuO
- Diamagnetism of YBaCuO crystals above ~: evidence for Gaussian fluctuations
- Universal superconducting precursor in the cuprates
- Phase-sensitive Harmonic Measurements of Microwave Nonlinearities in Cuprate Thin Films
- Generalization of Anderson's Theorem for Disordered Superconductors
- Fluctuational Anomalous Hall and Nernst Effects in Superconductors