Optical spectroscopy study of charge density wave order in Sr₃Rh₄Sn₁₃ and (Sr_0.5Ca_0.5)₃Rh₄Sn₁₃

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• 作者：W. J. Ban ; H. P. Wang ; C. W. Tseng…
• 关键词：charge density wave ; optical spectroscopy ; intermetallic compounds
• 刊名：Science China Physics, Mechanics & Astronomy
• 出版年：2017
• 出版时间：April 2017
• 年：2017
• 卷：60
• 期：4
• 全文大小：
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics, general; Classical and Continuum Physics; Astronomy, Observations and Techniques;
• 出版者：Science China Press
• ISSN：1869-1927
• 卷排序：60

文摘

We perform optical spectroscopy measurement on single-crystal samples of Sr₃Rh₄Sn₁₃ and (Sr_0.5Ca_0.5)₃Rh₄Sn₁₃. Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the phase transitions. The existence of residual Drude components in σ₁(ω) below T_CDW indicates that the Fermi surface is only partially gapped in the CDW state. The obtained value of 2Δ/k_BT_CDW is roughly 13 for both Sr₃Rh₄Sn₁₃ and (Sr_0.5Ca_0.5)₃Rh₄Sn₁₃ compounds, which is considerably larger than the mean-field value based on the weak-coupling BCS theory. The measurements provide optical evidence for the strong coupling characteristics of the CDW phase transition.