Landau renormalizations of superfluid density in the heavy-fermion superconductor CeCoIn5.
Landau renormalizations of superfluid density in the heavy-fermion superconductor CeCoIn5.
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DOI：
10.1103/physrevlett.113.166401
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发表时间：
2014-10
影响因子：
8.6
通讯作者：
L. Shu;D. MacLaughlin;C. Varma;O. Bernal;P. Ho;R. H. Fukuda;X. Shen;M. Maple
中科院分区：
文献类型：
--
作者：
L. Shu;D. MacLaughlin;C. Varma;O. Bernal;P. Ho;R. H. Fukuda;X. Shen;M. Maple
重费米子带的形成可以通过近藤效应和随之而来的巨大的费米液体重整化将周期性的局域矩阵列转换为巡回电子来实现。Leggett预言，对于液体（3）He，费米液体重整化在超导态发生变化，导致伦敦穿透深度Λ与温度的关系与BCS理论中的结果完全不同。利用莱格特的理论，经过重费米子的修正，可以从高质量样品中测量到的Λ的温度依赖性中提取出朗道参数F（0）（s）和F（1）（s）;这在以前从未实现过。与Λ相关的电子比热C（el）的温度依赖性的修改也是预期的。我们通过μ子自旋弛豫率测量仔细确定了CeCoIn（5）中Λ的大小和温度依赖性，得到F（0）（s）= 36 ± 1和F（1）（s）= 1.2 ± 0.3，并且我们发现C（el）的温度依赖性发生一致变化。这是在重费米子复合物中第一次确定F（1）（s）的值为<$F（0）（s），测试了重费米子理论的基本假设，即自能的频率依赖性比其动量依赖性重要得多。
The formation of heavy-fermion bands can occur by means of the conversion of a periodic array of local moments into itinerant electrons via the Kondo effect and the huge consequent Fermi-liquid renormalizations. Leggett predicted for liquid (3)He that Fermi-liquid renormalizations change in the superconducting state, leading to a temperature dependence of the London penetration depth Λ quite different from that in BCS theory. Using Leggett's theory, as modified for heavy fermions, it is possible to extract from the measured temperature dependence of Λ in high quality samples both Landau parameters F(0)(s) and F(1)(s); this has never been accomplished before. A modification of the temperature dependence of the electronic specific heat C(el), related to that of Λ, is also expected. We have carefully determined the magnitude and temperature dependence of Λ in CeCoIn(5) by muon spin relaxation rate measurements to obtain F(0)(s) = 36 ± 1 and F(1)(s) = 1.2 ± 0.3, and we find a consistent change in the temperature dependence of C(el). This, the first determination of F(1)(s) with a value ≪ F(0)(s) in a heavy-fermion compound, tests the basic assumption of the theory of heavy fermions, that the frequency dependence of the self-energy is much more important than its momentum dependence.