Laser-Matter Interaction on Ultrafast Timescale

When quantum materials are driven far from equilibrium by intense laser excitation, their properties can be dramatically modified. A variety of intriguing non-equilibrium phenomena can emerge, including charge transfer, ultrafast demagnetization, structural phase transitions, polarization switching, and even light-induced superconductivity. Experimentally, ultrafast laser sources provide direct access to electron and lattice dynamics on their intrinsic timescales, enabling the manipulation of transient quantum states of matter. We aim to uncover, control, and ultimately engineer non-equilibrium physical and chemical properties in materials using tailored laser pulses, by exploiting the coupled dynamics of spin, charge, and lattice degrees of freedom.

Selected Publications

Zhou, Z., Li, M., Frauenheim, T. and He, J., Controlling ultrafast magnetization dynamics via coherent phonon excitation in a ferromagnet monolayer. Nano Letters, 24(39), 12062-12069 (2024).
He, J., Li, S., Bandyopadhyay, A. and Frauenheim, T., Unravelling photoinduced interlayer spin transfer dynamics in two-dimensional nonmagnetic-ferromagnetic van der Waals heterostructures. Nano Letters, 21(7), pp.3237-3244. (2021)
He, J. and Frauenheim, T., Optically driven ultrafast magnetic order transitions in two-dimensional ferrimagnetic MXenes. The Journal of Physical Chemistry Letters, 11(15), 6219-6226 (2020).
Li, M. and He, J., Terahertz laser pulse boosts interlayer spin transfer in two-dimensional van der waals magnetic heterostructures. The Journal of Physical Chemistry Letters, 14(50), 11274-11280 (2023).
He, J., Frauenheim, T. and Li, S., Ultrafast chiral precession of spin and orbital angular momentum induced by circularly polarized laser pulse in elementary ferromagnets. The Journal of Physical Chemistry Letters, 15(9), 2493-2498 (2024).