Robust charge-density wave strengthened by electron correlations in monolayer 1T-TaSe2 and 1T-NbSe2
Year: 2021
Type: article
Abstract: Combination of low-dimensionality and electron correlation is vital for exotic quantum phenomena such as the Mott-insulating phase and high-temperature superconductivity. Transition-metal dichalcogenide (TMD) 1T-TaS 2 has evoked great interest owing to its unique nonmagnetic Mott-insulator nature coupled with a charge-density-wave (CDW). To functionalize such a complex phase, it is essential to enhance the CDW-Mott transition temperature T CDW-Mott , whereas this was difficult for bulk TMDs with T CDW-Mott < 200 K. Here we report a strong-coupling 2D CDW-Mott phase with a transition temperature onset of ~530 K in monolayer 1T-TaSe 2 . Furthermore, the electron correlation derived lower Hubbard band survives under external perturbations such as carrier doping and photoexcitation, in contrast to the bulk counterpart. The enhanced Mott-Hubbard and CDW gaps for monolayer TaSe 2 compared to NbSe 2 , originating in the lattice distortion assisted by strengthened correlations and disappearance of interlayer hopping, suggest stabilization of a likely nonmagnetic CDW-Mott insulator phase well above the room temperature. The present result lays the foundation for realizing monolayer CDW-Mott insulator based devices operating at room temperature.
Source: Nature Communications
Authors: Yuki Nakata, Katsuaki Sugawara, Ashish Chainani, Hirofumi Oka, Changhua Bao, Shaohua Zhou, Pei-Yu Chuang, Cheng-Maw Cheng, Tappei Kawakami, Yasuaki Saruta, Tomoteru Fukumura, Shuyun Zhou, Takashi Takahashi, Takafumi Sato
Institutions: Tohoku University, Advanced Institute for Materials Research, Tohoku University, National Synchrotron Radiation Research Center, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Frontier Science Center for Quantum Information of the Ministry of Education of China
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,560
Funders: Sumitomo Foundation, Ministry of Education, Culture, Sports, Science and Technology, National Natural Science Foundation of China, Tsinghua University, Beijing Innovation Center for Future Chip, National Synchrotron Radiation Research Center, Japan Society for the Promotion of Science, Division of Materials Research, Core Research for Evolutional Science and Technology, Precursory Research for Embryonic Science and Technology
Awards: G1001434161, G1179568690, G2664857127, Emergence of edge properties in atomic-layer materials by combining electronic structure imaging and first-principles calculation, Superconductivity and spin-orbit interaction in atomically thin films studied by ARPES, Search for exotic quasiparticles by angle-resolved photoemission spectroscopy, G4384028635, G4867240298, G5338727572, G554186272, G641733885, G6718509927, G7262807618, G7987901407, G8767082052
OpenAlex ID: W3204588778