When Photons Meet Quantum Materials
Research Interests
Dr. Yi Lin focuses on studying the behavior of electrons in the equilibrium or excited phases of materials. He directly visualizes the electronic band structure of materials using angle-resolved photoemission spectroscopy (ARPES). He combines strong laser pulses with pump-probe techniques to induce ultrafast, light-driven, and metastable phases in materials with exotic dimensionality, topology, conductivity, and order. His research has an overarching mission: to discover new materials and reveal hidden modes of light-matter interactions, aiming to guide next-generation energy-harvesting, optoelectronic, and sensing devices.
For his group at UA, he seeks to synergize both in-house facilities and user facilities at national labs to conduct interdisciplinary research. This includes developing photonics-integrated photoemission spectroscopy (π-ARPES) to explore strong light-matter interactions, investigating light-switchable materials and mechanisms to achieve ultrafast sensing and communication, and fabricating optically activable periodic defects in 2D materials to advance quantum science and technology
A portfolio of advanced table-top home facilities, synchrotron-based user facilities and strong computational collaborations...
Everything about light-induced ultrafast dynamics, photon-driven phase transitions and active manipulations of photoexcited states of quantum materials...
Highlights
A three-minute SLAM in plain language for general audience to have a glance of my research
A Love Story in One-Trillionth of A Second
Physics behind the SLAM:
In photoexcited semiconductors, the correlations between electrons and holes have been studied extensively either in screened free carriers at high excitation densities or in bound excitons at low densities. However, the crossover region between the two ends has been rarely explored. In fact, this crossover is critical and serves as the missing puzzle piece for understanding thoroughly the electron-hole correlation and its ultrafast dynamics in photoexcited materials. In my research, I directly visualize and study the ultrafast crossover in monolayer molybdenum disulfide at 80K via my novel application of extreme-ultraviolet time-resolved photoemission spectroscopy at Berkeley National Lab.
A 20-minute workshop recording for ARPES experts
Contributed Talk in CORPES22 displayed at 56:29
Talk Title: Exotic Band Renormalization Induced by Excitonic Correlations Revealed by XUV-trARPES
Talk Abstract: We report an ultrafast increase of the quasi-particle bandgap and effective mass in photoexcited monolayer MoS2 on HOPG, utilizing extreme-ultraviolet time- and angle-resolved photoemission spectroscopy (XUV-trARPES). Combined with theoretical models, we attribute these compelling band renormalizations to the excitonic effects from bound electron-hole pairs.
A 30-minute conference recording for general experts
Invited Talk in 2022 CLEO Conference
Talk Title: Revealing exciton-driven band renormalizations in 2D semiconductors by XUV-trARPES
Talk Abstract: https://opg.optica.org/abstract.cfm?uri=CLEO_QELS-2022-FTu4B.1