DCMPMS Seminars

Lightwave Spectroscopy: Attosecond Vision and Control of Electron Dynamics in Quantum Systems

by Dr. Shubhadeep Biswas ((Stanford University,USA))

Friday, September 15, 2023 from to (Asia/Kolkata)
at Join Zoom Meeting https://zoom.us/j/91043635496 Meeting ID: 910 4363 5496 Passcode: 680332
Description Direct access to the oscillations of the electric field within light grants a remarkable capability to achieve sub-cycle attosecond (1 as = 10-18 sec) time resolution. This level of precision is essential for the observation and manipulation of electronic behavior in matter, operating on its natural timescale [1, 2].
In this presentation, I would like to present the fascinating realm of lightwave metrology [3, 4] and its profound impact on the ability to visualize ultrafast processes within unique quantum systems. These insights are virtually unattainable through conventional pump-probe spectroscopy methods.
In particular, I shall show the time resolved dynamic information when an electron moves within a large molecular system probing its microscopic environment [5] or what happens to a plasmonic system in the quantum limit as it undergoes excitation into the collective modes [6].
Furthermore, I shall demonstrate how meticulously designed lightwaves, under sub-cycle control, can be harnessed to coherently engineer the band structure and topological properties of two-dimensional quantum systems [7]. This also manifests a new regime of fundamental symmetry driven Valleytronic [8] operation, which makes it universal, non-material-specific, non-excitation light-specific [7]. This innovative approach holds the potential to serve as the foundation for the next generation of dissipation-less lightwave-electronics operating in the petahertz (PHz) range.
1. Hentschel, M. et al. Attosecond metrology. Nature 414, 509-513 (2001).
2. Corkum, P. B. & Krausz, F. Attosecond science. Nature Physics 3, 381 (2007).
3. Mitra, S., Biswas, S. et al. Suppression of individual peaks in two-colour high harmonic generation. Journal of Physics B: Atomic Molecular and Optical Physics 53, 134004 (2020).
4. Schotz, J., Biswas, S. et al. Phase-Matching for Generation of Isolated Attosecond XUV and Soft-X-Ray Pulses with Few-Cycle Drivers. Physical Review X 10, 041011 (2020).
5. Biswas, S. et al. Probing molecular environment through photoemission delays. Nature Physics 16, 778-783 (2020).
6. Biswas, S. et al., Attosecond correlated electron dynamics at C60 giant plasmon resonance. arXiv:2111.14464 (2022) (Under review of Science).
7. Mitra, S. et al.,…., Biswas, S. Lightwave-controlled band engineering in quantum materials. arXiv:2303.13044 (2023) (Under review of Nature).
8. Schaibley, J. R. et al. Valleytronics in 2D materials. Nature Reviews Materials 1, 16055 (2016).