The evolution of electron correlation and charge density wave （CDW） in 1T-TaS2 single crystal has been investi- gated by temperature-dependent Raman scattering, which undergoes two obvious peaks of Aig modes about 7...The evolution of electron correlation and charge density wave （CDW） in 1T-TaS2 single crystal has been investi- gated by temperature-dependent Raman scattering, which undergoes two obvious peaks of Aig modes about 70.8 cm-t and 78.7 cm I at 80 K, respectively. The former peak at 70.8 cm-t is accordant with the lower Hubbard band, resulting in the electron-correlation-driven Mott transition. Strikingly, the latter peak at 78.7 cm-1 shifts toward low energy with increasing the temperature, demonstrating the occurrence of nearly commensurate CDW phase （melted Mott phase）. In this case, phonon transmission could be strongly coupled to commensurate CDW lattice via Coulomb interaction, which likely induces appearance of hexagonal domains suspended in an interdomain phase, composing the melted Mott phase characterized by a shallow electron pocket. Combining electronic structure, atomic structure, transport properties with Ra- man scattering, these findings provide a novel dimension in understanding the relationship between electronic correlation, charge order, and phonon dynamics.展开更多
The phase diagram of the one-dimensional Bose-Hubbard model describing interacting bosons in optical lattice is investigated with the variational approach. This method can also be generalized to the two-dimensional case.
基金The project supported in part by National Natural Science Foundation of China and the Natural Science Foundation of Zhejiang Province of China. We acknowledge useful discussions with X. Feng, T. Xiang, and Y. Yu.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51771126 and 11774247)the Youth Foundation of Science and Technology Department of Sichuan Province,China(Grant No.2016JQ0051)the World First-Class University Construction Funding
文摘The evolution of electron correlation and charge density wave （CDW） in 1T-TaS2 single crystal has been investi- gated by temperature-dependent Raman scattering, which undergoes two obvious peaks of Aig modes about 70.8 cm-t and 78.7 cm I at 80 K, respectively. The former peak at 70.8 cm-t is accordant with the lower Hubbard band, resulting in the electron-correlation-driven Mott transition. Strikingly, the latter peak at 78.7 cm-1 shifts toward low energy with increasing the temperature, demonstrating the occurrence of nearly commensurate CDW phase （melted Mott phase）. In this case, phonon transmission could be strongly coupled to commensurate CDW lattice via Coulomb interaction, which likely induces appearance of hexagonal domains suspended in an interdomain phase, composing the melted Mott phase characterized by a shallow electron pocket. Combining electronic structure, atomic structure, transport properties with Ra- man scattering, these findings provide a novel dimension in understanding the relationship between electronic correlation, charge order, and phonon dynamics.
文摘The phase diagram of the one-dimensional Bose-Hubbard model describing interacting bosons in optical lattice is investigated with the variational approach. This method can also be generalized to the two-dimensional case.
