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Microwave Absorption Peaks : Signatures of Spin Dynamics in Cuprates

S. Sridhar·Z. Zhai·A. Erb
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Abstract

We show that a common feature of temperature-dependent microwave absorption is the presence of absorption peaks. $ac$ loss peaks can arise when the internal $T$-dependent magnetic relaxation time crosses the measurement frequency. These features are observed in the \QTR{em}{insulating} ($Sr_{x}Ca_{14-x}Cu_{24}O_{41}$, $La_{5/3}Sr_{1/3}NiO_{4}$ and $YBa_{2}Cu_{3}O_{6.0}$), \QTR{em}{pseudo-gap} ($T>T_{c}$ in underdoped $YBa_{2}Cu_{3}O_{7-δ}$, $Hg:1223$ and $Hg:1201$) and \QTR{em}{superconducting} ($T<T_{c}$) states of the oxides. The commonality of these features suggests a magnetic (spin) mechanism, rather than a quasiparticle origin, for the so-called ``conductivity'' peaks observed in the cuprate superconductors.

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S. Sridhar, Z. Zhai, A. Erb. 1999-06-17. Microwave Absorption Peaks : Signatures of Spin Dynamics in Cuprates. https://arxiv.org/abs/cond-mat/9906053

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