Optical study of the electronic phase transition of strongly correlated YbInCu_4

• Published in: arXiv.org
• Main Authors: Garner, Sean R, Hancock, Jason N, Rodriguez, Yvonne W, Schlesinger, Zack, Bucher, Benno, Fisk, Zach, Sarrao, John L
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 10.07.2000
• Subjects: Phase transitions
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0007165

Infrared, visible and near-UV reflectivity measurements are used to obtain conductivity as a function of temperature and frequency in YbInCu_4, which exhibits an isostructural phase-transition into a mixed-valent phase below T_v=42 K. In addition to a gradual loss of spectral weight with decreasing temperature extending up to 1.5 eV, a sharp resonance appears at 0.25 eV in the mixed-valent phase. This feature can be described in terms of excitations into the Kondo (Abrikosov-Suhl) resonance, and, like the sudden reduction of resistivity, provides a direct reflection of the onset of coherence in this strongly correlated electron system.