Photon Science Seminar: "Disorder-driven decoherence in solid-state attosecond dynamics," David Purschke, University of Rochester

Abstract
Recently, there has been a great deal of interest in the area of attosecond quantum optics. While research has shown that extreme quantum light—bright-squeezed vacuum—can be used to control high-harmonic generation and distribute entanglement over a broad range of frequencies, little attention has been paid to the role of decoherence in strong-field quantum optical processes. This stems in part from the lack of a general understanding into the nature of decoherence in the sub-cycle dynamics of electron-hole pairs. I will discuss our recent results probing high-harmonic generation in silicon amorphized by ion implantation and show how structural disorder leads to a trajectory-dependent decoherence that is imprinted onto the roll off of the HHG spectrum. Furthermore, I will discuss new directions of solid-state attosecond science and bright quantum light enabled by mid-infrared laser development at the Laboratory for Laser Energetics.

Bio
David Purschke is a scientist in the Ultrafast Plasma Photonics Group at the University of Rochester Laboratory for Laser Energetics (LLE). His research focuses on ultrafast light-matter interaction from terahertz to extreme ultraviolet. He completed his PhD in 2021 in the group of Prof. Frank Hegmann where he studied ultrafast terahertz dynamics in nanomaterials. Subsequently, he was an NRC & NSERC Postdoctoral Fellow at the Joint Attosecond Science Laboratory at the National Research Council and University of Ottawa, where he studied solid-state attosecond dynamics and attosecond quantum optics with Prof. Giulio Vampa. In 2025, David started a new appointment as a Scientist in the PULSE Division at the LLE, where his research focuses on new applications in ultrafast optics enabled by emerging mid-infrared lasers.