T. Jacobs

Quantitative analysis of nonlinear microwave surface impedance from non‐Lorentzian resonances of high Q resonators

A method of analyzing the response of nonlinear high Q resonant circuits, such as superconducting microwave cavities, is presented. The method enables one to extract the nonlinear surface impedance, Zs(Hrf), from the complex transmission amplitude, S21(f), as frequency, f, is swept across the resonance. Sensitivity to small changes in the microwave field strength (ΔHrf<1 mOe) can thus be obtained.

Evidence for multi-component superconducting order parameter from microwave measurements of YBa2Cu3O7−δ single crystals

Abstract The microwave complex conductivity in the superconducting state ( σ s = σ 1 − iσ 2 ) of high quality YBa 2 Cu 3 O 7− δ single crystals measured at 10 GHz using a high- Q Nb cavity reveal two new features - (i) A new peak in σ 1 at ∼ 80 K and (ii) enhanced pair conductivity σ 2 below ∼ 65 K . The results indicate two pairing temperature scales and point to a multi-component superconducting order parameter in YBCO .

In-plane and c-circumflex-axis microwave penetration depth of Bi2Sr2Ca1Cu2O8+ delta crystals.

The complete temperature dependences of the in-plane and {cflx {ital c}}-axis microwave (10 GHz) penetration depth {lambda}({ital T}) and the surface resistance {ital R}{sub {ital s}}({ital T}) of high quality Bi{sub 2}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub 8+{delta}} crystals are reported. In contrast to earlier measurements, a leading {lambda}{sub {ital ab}}{proportional_to}{ital T} dependence is observed at low temperatures, consistent with nodes in the in-plane gap. The overall behavior of {lambda}{sub {ital ab}}({ital T}) and {ital R}{sub {ital sab}}({ital T}) is similar to that of YBa{sub 2}Cu{sub 3}O{sub {ital y}} at low {ital T}, but differs at temperatures near {ital T}{sub {ital c}}. The {cflx {ital c}}-axis penetration depth {lambda}{sub {ital c}}({ital T}) is shown to best agree with a model of weakly coupled superconducting layers with nodes in the gap. {copyright} {ital 1995 The American Physical Society.}

Microwave response of YBa 2 Cu 3 O 6.95 crystals: Evidence for a multicomponent order parameter

New features are reported in precision measurements of the complex microwave conductivity of high quality

MICROWAVE PROPERTIES OF BOROCARBIDE SUPERCONDUCTORS RNI2B2C (R=Y,ER,TM,HO)

YBa_{2}Cu_{3}O_{6.95}

New features in the microwave response of Y Ba2Cu3O6.95 crystals : Evidence for a multi-component order parameter

crystals grown in

Microwave response of YBa{sub 2}Cu{sub 3}O{sub 6.95} crystals: Evidence for a multicomponent order parameter

BaZrO_{3}

In-plane and {cflx {ital c}}-axis microwave penetration depth of Bi{sub 2}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub 8+{delta}} crystals

crucibles. A third peak in the normal conductivity,

Microwave Properties of Borocarbide Superconductors LnNi2B2C (Ln = Y, Er, Tm, Ho)

\sigma_{1}(T)

Microwave properties of borocarbide superconductors {ital R}Ni{sub 2}B{sub 2}C ({ital R}=Y,Er,Tm,Ho)

, at around