Department of Chemistry

Yusong Bai

Assistant Professor
GeoChem 347
Research Interests Ultrafast spectroscopy, Optical microscopy, Excitons, Quantum materials

Biography

Research Statement

Designing and harnessing quantum properties are at the core of quantum information sciences, and open new frontiers in contemporary chemistry and physics. Examples include controlling vibronic coherence and molecular exciton in chemistry, or engineering metal-insulator transition and superconductivity in condensed matter physics. We aim to develop “quantum knobs” that tune charge, spin, and orbital degrees of freedom by controlling interfacial interactions amongst molecular-to-nanoscale material entities and map the resultant emergent quantum effects using spectro-microscopies under cryogenic and magnetic conditions. Particularly, we focus on designing and probing correlated electron systems, strongly-interacting exciton systems, and 2D magnetic systems. These systems can undergo quantum phase transitions and form ordered ground states due to changes in fundamental parameters at a Hamiltonian level rather than the temperature in the more familiar thermal phase transitions. The research in the Bai Lab is highly interdisciplinary, bridging the frontiers of quantum research in condensed matter physics and materials design in contemporary chemistry: this laboratory will pioneer new concepts, phenomena, and functions that are defined by quantum emergence.

Education 

  • 2017 – Ph.D: Duke University 
  • 2011 – BS: Beijing University of Aeronautics and Astronautics

Publications

  • Bai, Y.*; Zhou, L.*; Wang, J.; Wu, W.; McGilly, L.; Halbertal, D.; Lo, C.; Liu, F.; Ardelean, J.; Rivera, P.; Finney, N.; Yang, X.-C.; Basov, D. N.; Yao, W.; Xu, X.; Hone, J.; Pasupathy, A.; Zhu, X.-Y. “Excitons in strain-induced one-dimensional moiré potentials at transition metal dichalcogenide heterojunctions”. Nat. Mater., 19, 1068-1073 (2020).
  • Jiang, T.*; Bai, Y.*; Zhang, P.; Han, Q.; Mitzi, D. B.; Therien, M. J. “Electronic structure and photophysics of a supermolecular iron complex having a long MLCT-state lifetime and panchromatic absorption”. Proc. Natl. Acad. Sci. U.S.A.117, 20430-20437 (2020).
  • Liu, F.; Wu, W.; Bai, Y.; Chae, S.; Li, Q.; Wang, J.; Hone, J.; Zhu X.-Y. “Disassembling 2D van der Waals crystals into macroscopic monolayers and reassembling into artificial lattices”. Science367, 903-906 (2020).
  • Wang, J.*; Ardelean, J.*; Bai, Y.*; Steinhoff, A.; Florian, M.; Wen, Q.; Jahnke, F.; Xu, X.; Kira, M.; Hone, J.; Zhu, X.-Y. “Optical generation of high carrier densities in 2D semiconductor hetero-bilayers”. Sci. Adv.5, eaax0145 (2019).
  • Bai, Y.; Olivier, J.-H.; Bullard, G.; Liu, C.; Therien, M. J. “Dynamics of charge excitons in electronically and morphologically homogeneous single-walled carbon nanotubes”. Proc. Natl. Acad. Sci. U.S.A.115, 674-679 (2018).
  • Bai, Y.; Bullard, G.; Olivier, J.-H.; Therien, M. J. “Quantitative evaluation of optical free carrier generation in semiconducting single-walled carbon nanotubes”. J. Am. Chem. Soc., 140, 14619-14626 (2018).
  • Bai, Y.; Olivier, J.-H.; Yoo, H.; Polizzi, N. F.; Park, J.; Rawson, J.; Therien, M. J. “Molecular road map to tuning ground state absorption and excited state dynamics of long-wavelength absorbers”. J. Am. Chem. Soc.139, 16946-16958 (2017).
  • Bai, Y.; Rawson, J.; Roget, S. A.; Olivier, J.-H.; Lin, J.; Zhang, P.; Beratan, D.; Therien, M. J. “Controlling the excited-state dynamics of low band gap near-infrared absorbers via proquinoidal unit electronic structural modulation”. Chem. Sci.8, 5889-5901 (2017).