We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13. Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the ph...We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）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 Tcow indicates that the Fermi surface is only partially gapped in the CDW state. The obtained value of 2A/kBTcow is roughly 13 for both Sr3Rh4Sn13 and （Sr0.5Ca0.5）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.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11327806,and GZ1123)the National Key Research and Development Program of China(Grant No.2016YFA0300902)the Ministry of Science and Technology of Taiwan(Grant No.MOST-103-2112-M-006-014-MY3)(CSL)
文摘We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）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 Tcow indicates that the Fermi surface is only partially gapped in the CDW state. The obtained value of 2A/kBTcow is roughly 13 for both Sr3Rh4Sn13 and （Sr0.5Ca0.5）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.
