High-order correlations and ultrafast Wigner negativities in bright-squeezed-vacuum-driven high-harmonic generation

@misc{delapena2026highorder,
  title = {{High-order correlations and ultrafast Wigner negativities in bright-squeezed-vacuum-driven high-harmonic generation}},
  author = {Sebastián de-la-Peña and Heiko Appel and Marcelo F. Ciappina and Ofer Neufeld and Angel Rubio},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.20559},
  eprint = {2609.20559},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.20559},
}

TY  - UNPB
TI  - High-order correlations and ultrafast Wigner negativities in bright-squeezed-vacuum-driven high-harmonic generation
AU  - Sebastián de-la-Peña
AU  - Heiko Appel
AU  - Marcelo F. Ciappina
AU  - Ofer Neufeld
AU  - Angel Rubio
PY  - 2026
DA  - 2026/09/17
PB  - arXiv
DO  - 10.48550/arxiv.2609.20559
UR  - https://arxiv.org/abs/2609.20559
AB  - High-harmonic generation (HHG) is a prototypical strong-field process in which intense light drives matter to emit radiation at integer multiples of the driving frequency. Extending HHG into the quantum-optical regime offers new opportunities to probe and control strongly nonlinear light-matter interactions using nonclassical states of light. Yet describing this regime requires a fully quantum treatment of the correlated electron-photon dynamics, which becomes computationally challenging for broadband, strongly squeezed fields. Here we solve the quantum-electrodynamical dynamics of a two-level system driven by bright squeezed vacuum in a converged multimode Hilbert space. Both the driving field and emitted harmonics are fully quantized, with the light-matter interaction treated nonperturbatively. This enables direct access to the multimode quantum state and its higher-order correlations beyond semiclassical sampling or perturbative descriptions. We show that squeezed-vacuum driving produces harmonic emission with qualitatively distinct second- and third-order photon correlations compared with coherent excitation. Moreover, back-action from the driven emitter strongly reshapes the incident squeezed field, generating pronounced Wigner-function negativities that evolve on attosecond timescales. Our results establish a fully quantum framework for broadband strong-field dynamics with squeezed light and provide a route to predicting and interpreting quantum-HHG experiments and their extension to more complex emitters.
ER  -