Hierarchy of approximations for describing quantum light from high-harmonic generation: A Fermi-Hubbard model study
arXiv:2410.19533 · doi:10.1103/PhysRevA.111.013113
Abstract
The quantum optical description of high-order harmonic generation where both the electrons of the generating medium and the driving and generated light fields are described quantum mechanically has been of significant interest in the past years. The quantum optical formulation leads to equations of motion for the generated light field in which the quantum optical field couples to the time-dependent current of the electronic medium irrespectively of the specifics of the electronic system being an atom, molecule, or solid. These equations of motion are not solvable for any realistic system and accurate and verified approximations are hence needed. In this work, we present a hierarchy of approximations for the equations of motion for the photonic state. At each level in this hierarchy, we compare it to the previous level justifying the validity using the Fermi-Hubbard model as an example of an electronic system with correlations. This model allows us to perform an accurate simulation of the electron motion of all the required states. We find that for the typical experimental situation of weak quantized-light-matter-coupling constant and at intensities well below the damage threshold, an explicit expression for the generated quantum light, referred to as the Markov-state approximation (MSA), captures the high-harmonic spectrum quantitatively and describes the single-mode quantum properties of the generated light as characterized by the Mandel-Q parameter and the degree of squeezing qualitatively.
References in corpus (23)
- Quantum information with continuous variables
- Symmetries and selection rules in Floquet systems: application to harmonic generation in nonlinear optics
- High harmonic imaging of ultrafast many-body dynamics in strongly correlated systems
- Generation of optical Schrödinger cat states in intense laser-matter interactions
- On the Quantum-Optical Nature of High Harmonic Generation
- High harmonic generation driven by quantum light
- Photon-statistics force in ultrafast electron dynamics
- Quantum electrodynamics of intense laser-matter interactions: A tool for quantum state engineering
- High Harmonic Generation by Bright Squeezed Vacuum
- Light emission from strongly driven many-body systems
- High-harmonic generation in one-dimensional Mott insulator
- A general approach to few-cycle intense laser interactions with complex atoms
- Entanglement and squeezing of the optical field modes in high harmonic generation
- Strong laser fields and their power to generate controllable high-photon-number coherent-state superpositions
- Electron-correlation induced nonclassicallity of light from high-harmonic generation
- Evidence of the quantum-optical nature of high-harmonic generation
- Correlation effects in high-harmonic generation from finite systems
- A quantum optical description of photon statistics and cross-correlations in high harmonic generation
- Explicit schemes for time propagating many-body wavefunctions
- Doping effects in high-harmonic generation from correlated systems
- Absence of quantum optical coherence in high harmonic generation
- Squeezed states of light after high-harmonic generation in excited atomic systems
- Noninteger high-harmonic generation from extended correlated systems