Disorder-driven decoherence in solid-state attosecond dynamics
David Purschke | University of Rochester
Abstract:
Femtosecond lasers create flashes of coherent light with unimaginably short pulse durations, providing an ultrafast window into the quantum dynamics of matter. Recently, the mid-infrared has emerged as an important spectral range, and is an excellent starting point for generating both long-wavelength terahertz radiation and short-wavelength x-rays for attosecond science. Furthermore, the low photon energy facilitates field driven processes such as tunneling and high-harmonic generation in semiconductors and insulators. In high-harmonic generation, the strong laser field tears apart electrons and holes from their bound states and launches them on recolliding trajectories that explore the local energy landscape. In this talk, I will discuss recent results studying amorphized silicon driven by intense mid-infrared light [1]. I will show how local disorder on few-nm length scales – deeply subwavelength relative to the mid-infrared wavelength – is imprinted into the high-harmonic generation spectrum, revealing hidden medium-range order and enabling us to estimate the correlation length. Furthermore, and time permitting, I will discuss new research avenues of my group at the Laboratory for Laser Energetics, including novel sources of mid-infrared bright quantum light [2] and coherent control of near-field ultrabroadband RF in laser-plasma channels [3].
[1] Purschke et al. “Giant enhancement of attosecond tunnel ionization competes with disorder-driven decoherence in amorphized silicon,” arXiv:2511.14678
[2] Lemieux et al. “Photon bunching in high-harmonic emission controlled by quantum light,” Nature Photonics 19 (2025)
[3] Garrett et al. “Detection of surface waves during femtosecond filamentation,” Physical Review E 111 (2025)
Location: QNC 1201