Microwave determination of the quasiparticle scattering time in
- 1 May 1993
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 47 (17), 11314-11328
- https://doi.org/10.1103/physrevb.47.11314
Abstract
We report microwave surface resistance () measurements on two very-high-quality crystals which exhibit extremely low residual loss at 1.2 K (2-6 μΩ at 2 GHz), a broad, reproducible peak at around 38 K, and a rapid increase in loss, by 4 orders of magnitude, between 80 and 93 K. These data provide one ingredient in the determination of the temperature dependence of the real part of the microwave conductivity, (T), and of the quasiparticle scattering time. The other necessary ingredient is an accurate knowledge of the magnitude and temperature dependence of the London penetration depth, λ(T). This is derived from published data, from microwave data of Anlage, Langley, and co-workers and from, high-quality μSR data. We infer, from a careful analysis of all available data, that (0)/(T) is well approximated by the simple function 1-, where t=T/, and that the low-temperature data are incompatible with the existence of an s-wave, BCS-like gap. Combining the and λ(T) data, we find that (T), has a broad peak around 32 K with a value about 20 times that at . Using a generalized two-fluid model, we extract the temperature dependence of the quasiparticle scattering rate which follows an exponential law, exp(T/), where ≊12 K, for T between 15 and 84 K. Such a temperature dependence has previously been observed in measurements of the nuclear spin-lattice relaxation rate. Both the uncertainties in our analysis and the implications for the mechanism of high-temperature superconductivity are discussed.
Keywords
This publication has 40 references indexed in Scilit:
- Growth and properties of superconducting YBCO single crystalsPhysica C: Superconductivity and its Applications, 1992
- Quasiparticle damping in andPhysical Review Letters, 1992
- Penetration depth and microwave loss measurements with a YBa2Cu3O7−δ/LaAlO3/YBa2Cu3O7−δ trilayer transmission lineApplied Physics Letters, 1991
- Incommensurate magnetic fluctuations inPhysical Review Letters, 1991
- Dynamic conductivity and coherence peak in superconductorsPhysical Review Letters, 1991
- Anomalous behavior of nuclear spin-lattice relaxation rates in belowPhysical Review Letters, 1991
- Application of antiferromagnetic-Fermi-liquid theory to NMR experiments inPhysical Review B, 1991
- In a clean high-superconductor you do not see the gapPhysical Review Letters, 1990
- "Normal" Tunneling and "Normal" Transport: Diagnostics for the Resonating-Valence-Bond StatePhysical Review Letters, 1988
- Possible highT c superconductivity in the Ba?La?Cu?O systemZeitschrift für Physik B Condensed Matter, 1986