A5011132161- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Organic and Molecular Conductors Research
- Topological Materials and Phenomena
- Iron-based superconductors research
- Rare-earth and actinide compounds
- 2D Materials and Applications
Shanghai Jiao Tong University
2022-2025
The interplay between different degrees of freedom governs the emergence correlated electronic states in quantum materials, with charge density waves (CDW) often coexisting other exotic phases. Under thermal equilibrium, traditional CDW are consequentially accompanied by structural phase transitions. In contrast, ultrafast photoexcitation allows access to where a single degree dominates time domain, enabling study underlying physics without interference. Here, we report realization...
The ultrafast electronic structures of the charge density wave material 1T-TiSe_{2} were investigated by high-resolution time- and angle-resolved photoemission spectroscopy. We found that quasiparticle populations drove phase transitions in within 100 fs after photoexcitation, a metastable metallic state, which was significantly different from equilibrium normal phase, evidenced far below transition temperature. Detailed pump-fluence-dependent experiments revealed photoinduced state result...
High-resolution time- and angle-resolved photoemission measurements were made on FeSe superconductors. With ultrafast photoexcitation, two critical excitation fluences that correspond to electronic phase transitions found only in the $d_{yz}$-orbit-derived band near Brillouin-zone center within our time energy resolution. Upon comparison detailed temperature dependent measurements, we conclude there are equilibrium (at approximately 90 120 K) above superconducting transition temperature, an...
We present the development of a high-precision sample-position-autocorrection system for photoemission experiments. A binocular vision method based on image pattern matching calculations was realized to track sample position with an accuracy better than 1 µm, which much smaller spot size incident laser. illustrate performance representative data topological insulator Bi2Se3 and optimally doped cuprate superconductor Bi2Sr2CaCu2O8+δ. Our provides new possibilities studying...