Pressure evolution of f electron hybridized state in CeCoIn5 studied by optical conductivity
Pressure evolution of f electron hybridized state in CeCoIn5 studied by optical conductivity
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光导研究CeCoIn5中f电子杂化态的压力演化
DOI：
10.1088/1742-6596/592/1/012001
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Y. Ikemoto
中科院分区：
文献类型：
--
作者：
H. Okamura;A. Takigawa;E. D. Bauer;T. Moriwaki;Y. Ikemoto
在高压至8 GPa和低温至6 K下测量了CeCoIn 5的光学电导率σ (ω)，研究了费米能级附近传导(c)-f电子杂化态的压力演化。在常压下，CeCoIn 5是一种重费米子超导体，tc = 2.3 K，具有中等强度的cf杂化。在环境压力下，由于cf杂化态的光激发，σ (ω)显示出一个明显的红外峰。随着压力的增加，红外峰变宽，中心向高能量偏移。这一结果表明，cf杂化态的大密度态随着压力的增加而变宽，并且态密度峰值远离费米能级。虽然从理论上考虑，人们已经广泛地假设了cf杂化态的这种压力演化，但目前的光学结果清楚而直接地证明了这一点。
Optical conductivity σ (ω) of CeCoIn 5 has been measured under high pressure to 8 GPa and at low temperatures to 6 K, to study the pressure evolution of the conduction (c)-f electron hybridized state near the Fermi level. At ambient pressure, CeCoIn 5 is a heavy fermion superconductor with T c= 2.3 K, and has moderately strong cf hybridization. σ (ω) at ambient pressure shows a marked infrared peak due to optical excitations involving the cf hybridized state. With increasing pressure, the infrared peak becomes broader, and its center shifts to higher energy. This result indicates that the large density of states of the cf hybridized state becomes broader with increasing pressure, and that the peak of the density of states shifts away from the Fermi level. Althouth such pressure evolution of the cf hybridized state had been widely assumed on the basis of theoretical consideration, the present optical result demonstrates it clearly and directly.