Qile Wu

Research

I have been working on theories that have direct impact on real-world experiment in the field of Quantum Optics and Condensed Matter Physics. Quantum Optics deals with fundamental phenomena in the interaction between light and matter. Condensed Matter Physics is concerned with the fundamental principles underlying the properties and behaviors of materials, which include all liquids and solid-state materials such as metals, insulators, and semiconductors. My theoretical work focuses on the overlap between Quantum Optics and Condensed Matter Physics, particularly fundamental processes in the interaction between strong lasers and solid-state materials. The goal is to discover new optical methods for experimentally extracting fundamental quantities that determine the properties of solid-state materials—how they respond to electricity and light, for example.

Specifically, I have been studying the physical process called high-order sideband generation (HSG), which is a nonperturbative nonlinear optical phenomenon in semiconductors that are simultaneously driven by a relatively weak near-infrared (NIR) laser and a sufficiently strong terahertz (THz) field. The study of HSG has led to the first experimental reconstruction of Bloch wavefunctions, which are physicists’ best source of information about what happens inside of electronic devices. The related experimental technique called high-order sideband polarimetry has already shown its capability in measuring quantities such as species-specific dephasing rates that are not accessible from other methods so far.

Selected Publications

1. S. D. O’Hara, J. B. Costello, Qile Wu, K. W. West, L. N. Pfeiffer, and M. S. Sherwin, Bloch-wave interferometry of driven quasiparticles in bulk GaAs, arXiv preprint arXiv:2305.12245 (2023).

2. J. B. Costello, S. D. O’Hara, Qile Wu, M. Jank, L. N. Pfeiffer, K. W. West, and M. S. Sherwin, Breaking a Bloch-wave interferometer: quasiparticle species-specific temperature-dependent nonequilibrium dephasing, Physical Review B, 108, 195205 (2023).

3. Qile Wu and Mark S. Sherwin, Explicit formula for high-order sideband polarization by extreme tailoring of Feynman path integrals, Physical Review B (Editors’ Suggestion), 107, 174308 (2023)

4. J. B. Costello, S. D. O’Hara, Qile Wu, D. C. Valovcin, L. N. Pfeiffer, K. W. West, and M. S. Sherwin, Reconstruction of Bloch wavefunctions of holes in a semiconductor, Nature, 599, 57-61 (2021).

5. H. B. Banks, Qile Wu, D. C. Valovcin, S. Mack, A. C. Gossard, L. Pfeiffer, R.-B. Liu, and M. S. Sherwin, Dynamical birefringence: electron-hole recollisions as probes of Berry curvature, Physical Review X, 7, 041042 (2017).