2024/12/05(Thu) 10:30 -12:00 五樓第一會議室 5F, 1st Meeting Room
Title
The growing charge-density-wave order in CuTe lightens and speeds up electrons
Speaker
朱明文特聘研究員 (國立台灣大學凝態科學研究中心) Dr. Ming-Wen Chu (Center for Condensed Matter Sciences, National Taiwan University)Abstract
Charge density waves (CDWs) are pervasive orders in solids that usually enhance the effective mass (m*) and reduce the Fermi velocity (vF) of carriers.
Here, we report on the inverse - a reduced m* and an enhanced vF correlated with the growth of the CDW order in CuTe with gapped, practically linearly dispersing bands - reminiscent of emergent CDW-gapped topological semimetals.
Using momentum-dependent electron energy-loss spectroscopy (q-EELS), we simultaneously capture m* and vF of the CDW-related, practically linearly dispersing electrons by plasmon dispersions across the transition (335 K), with m* of 0.28 m0 (m0, the electron rest mass) and vF of ~ 0.005c (c, the speed of light) at 300K. With the growth of the CDW order-parameter strength toward 100 K, the electrons become lighter and move faster by ~ 20%. Thorough inspection below the transition temperature unveils the essential role of the increasing opening of the CDW gap. CuTe is a rich platform for the exploration of CDW/correlation physics with q-EELS established as a useful probe for this type of physics.
Language
演講語言 (Language): in English
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