Presentation Information
[2G09]Enhancement of superconductivity by charge density wave disorder in layered superconductor NbTe2
*Takaya Shimokawa1, Yukiko Obata1, Yuya Kaneko1, Hiro Takada1, Kaito Sato1, Hayato Makino1, Kazutoshi Shimamura2, Hiroyuki Okamoto3, Masashi Ohashi1, Masao Obata1, Tatsuki Oda1, Yasuo Yoshida1 (1. Department of Physics, Kanazawa University, 2. Engineering and Technology Department, Kanazawa University, 3. Division of Health Sciences, Kanazawa University)
The complex interplay between superconductivity (SC) and charge density wave (CDW), both driven by electron–phonon coupling, is a central topic in the study of transition metal dichalcogenide (TMD) superconductors. Here, we report a remarkable enhancement of Tc from 0.5 K to 2.5 K induced by disorder in the TMD superconductor NbTe2, in which SC coexists with two distinct CDW components (CDW1 and CDW2). Scanning tunneling microscopy and spectroscopy (STM/S) reveal that CDW1 induces strong DOS modulation, while CDW2 shows weak modulation in the standard sample. In contrast, in the disordered sample, the DOS modulation of CDW1 becomes weaker, and CDW2 no longer exists. We conclude that the complicity of CDW ordering near the disappearance of CDW2 plays a key role in enhancing superconductivity in NbTe2. These results highlight a novel mechanism in which electronic inhomogeneity, rather than simple CDW suppression, contributes to Tc enhancement.