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Résumé |
Faraday waves, typically observed in driven fluids, result from the confluence of nonlinearity,
parametric amplification and dispersion. In this talk I’ll show that optical pulses can generate
analogous phenomena in quantum materials.
First we’ll discuss how light-driven optical phonons can induce spatiotemporal orders, where
material properties oscillate at an incommensurate wavevector in space and at half the drive
frequency in time [1]. The order is surprisingly robust against temperature. Predictions for time-
resolved diffraction and suggestions for candidate materials will be presented [2].
Next I’ll present a theory of ultrafast light-matter interactions for a quantum material with a
continuous broken symmetry, one characterized by a gapped (Higgs) amplitude and a gapless
(Goldstone) phase. We’ll see that a dynamical nonlinear coupling between these two modes
drives an emergent phason texture that oscillates in space and in time: Faraday-Goldstone
waves. Calculated signatures of this spatiotemporal order compare well with existing
measurements on K0.3MnO3. We find that this light-generated crystalline state is robust to
thermal noise, even when the original Goldstone mode is not. Higgs-Goldstone beating,
associated with coherent energy exchange between these two modes, is also predicted [3].
Our results offer a new pathway for the design of periodic structures in quantum materials with
ultrafast light pulses.
[1] D. Kaplan, P.A. Volkov, A. Chakraborty, Z. Zhuang and PC, Physical Review Letters
134, 066902 (2025) (Editor’s Suggestion).
[2] D. Kaplan, P. A. Volkov, J. Coulter, S. Zhang, and PC, arXiv:2507.14110, (2025).
[3] D. Kaplan, P. A. Volkov, A. Cavalleri and PC, arXiv 2511.07320 (2025). |
