Speaker
Description
High-harmonic generation in correlated electronic systems has recently emerged as a sensitive probe of many-body interactions [1,2]. Still, the question on how long-range electronic coherence leaves its imprint on the emitted light and its photon statistics [3,4] remains largely unaddressed. η-pairing states [5] in the half-filled Hubbard model represent exact eigenstates exhibiting off-diagonal long-range order. Here we investigate how η-pairing correlations reshape the strong-field emission. We find pronounced differences compared to the Mott-insulating ground state in both the intensity and the photon statistics of the emitted field, accompanied by a pronounced squeezing of the harmonic emission in the η-state. This indicates that the statistical features of HHG carry diagnostic information about electronic order beyond what power spectra alone reveal. Finally, I will report on experimental progress towards experimental detection of the imprints of electronic correlations in the photon statistics of the emitted harmonics.
References:
[1] Silva et al., “High-harmonic spectroscopy of ultrafast many-body dynamics in strongly correlated systems”, Nat. Photonics 12, 266–270 (2018)
[2] Murakami et al., “High-Harmonic Generation in Mott Insulators“, Phys. Rev. Lett. 121, 057405 (2018).
[3] Lange et al., “Electron-correlation-induced nonclassicality of light from high-order harmonic generation”, Phys. Rev. A 109, 033110 (2024)
[4] Lange et al., “Excitonic Enhancement of Squeezed Light in Quantum-Optical High-Harmonic Generation from a Mott Insulator”, Phys. Rev. Lett. 135, 043603 (2025)
[5] Yang et al., “η-pairing and off-diagonal long-range order in a Hubbard model”, Phys. Rev. Lett. 63, 2144–2147 (1989)