89. Charge-Density-Wave Order And Electronic Phase Transitions in a Dilute D-Band Semiconductor

Huandong Chen, Boyang Zhao, Josh Mutch, Gwan Yeong Jung, Guodong Ren, Sara Shabani, Eric Seewald, Shanyuan Niu, Jiangbin Wu, Nan Wang, Mythili Surendran, Shantanu Singh, Jiang Luo, Sanae Ohtomo, Gemma Goh, Bryan C. Chakoumakos, Simon J. Teat, Brent Melot, Han Wang, Abhay N. Pasupathy, Rohan Mishra, Jiun-Haw Chu, Jayakanth Ravichandran

Adv. Mater. 2303283 (2023)

As one of the most fundamental physical phenomena, charge density wave (CDW) order predominantly occurs in metallic systems such as quasi-one-dimensional (quasi-1D) metals, doped cuprates, and transition metal dichalcogenides, where it is well understood in terms of Fermi surface nesting and electron-phonon coupling mechanisms. On the other hand, CDW phenomena in semiconducting systems, particularly at the low carrier concentration limit, are less common and feature intricate characteristics, which often necessitate the exploration of novel mechanisms, such as electron-hole coupling or Mott physics, to explain. In this study, we combined electrical transport, synchrotron X-ray diffraction and density-functional theory (DFT) calculations to investigate CDW order and a series of hysteretic phase transitions in a dilute d-band semiconductor, BaTiS₃. Our experimental and theoretical findings suggest that the observed CDW order and phase transitions in BaTiS₃ may be attributed to both electron-phonon coupling and non-negligible electron-electron interactions in the system. Our work highlights BaTiS₃ as a unique platform to explore CDW physics and novel electronic phases in the dilute filling limit and could open new opportunities for developing novel electronic devices.