Probing dephasing time of crystals via spectral properties of high-harmonic generation

TL;DR

This paper introduces a spectral interference model to probe the dephasing time in crystals via high-harmonic generation, linking spectral splittings to electron-hole dynamics and proposing an experimental scheme for measurement.

Contribution

It presents a novel spectral interference approach in momentum space to determine crystal dephasing times using high-harmonic spectra, advancing ultrafast spectroscopy techniques.

Findings

Spectral splittings are linked to temporal interference between harmonic channels.

A subfemtosecond resolution scheme for measuring dephasing time is proposed.

The model reproduces harmonic peaks and spectral splittings accurately.

Abstract

Coherent time is a characteristic time in the extreme nonlinear optics regime and thus generally introduced as the dephasing time in the simulations of the solid-state high-harmonic generation. This characteristic time linked with the coherent decay of quantum trajectory controls the emergence of the spectral splittings in the high harmonic spectroscopy, which can been attributed to the temporal interference between two adjacent harmonic emission channels. To reproduce the harmonic peaks and spectral splittings, a temporal two-slit interference model in the momentum space is introduced. In addition, mechanisms of spectral splitting provide a state-of-the-art avenue to probe the characteristic elapse between electron and hole. Based on the subfemtosecond resolution of the spectral interference opening and closing zones in the wavelength-dependent high-order harmonic spectra, we also propose an alternative scheme to probe the dephasing time of crystals by the feasible laser pulses in present experimental setups.