arXiv subjects

Eleftherios Goulielmakis

Publications and source records attributed to Eleftherios Goulielmakis.

5 recordsLinked to original sources

arXiv2026

Roadmap on Attosecond Science

Twenty-five years have passed since the first experimental demonstration of attosecond pulses, marking the advent of our ability to resolve and control electron motion in real time. What began as a technological breakthrough - generating the shortest flashes ever produced - has evolved into a powerful approach for probing and steering electronic dynamics in atoms, molecules, and solids. This roadmap, authored by leading experts in the field, surveys the recent rapid progress in the generation and characterization of attosecond pulses, emerging attosecond measurement and control techniques, and their expanding range of applications. It reviews current and future developments in attosecond light sources, including novel laser technologies, waveform synthesizers, new schemes for high-order harmonic generation, attosecond pulse generation at free-electron lasers, and structured light. Advances in attosecond measurement methodologies are also discussed, encompassing all-attosecond pump-probe spectroscopy, attosecond four-wave mixing, attosecond microscopy, spectroscopy with light transients, and attosecond interferometry. Furthermore, the roadmap addresses applications of attosecond spectroscopy to reveal electron dynamics in molecules and condensed matter systems from both theoretical and experimental perspectives, and highlights emerging directions at the interface with quantum optics and quantum entanglement. Overall, this work aims to serve as a comprehensive resource for navigating the evolving landscape of attosecond science.

physics.optics↗

arXiv2025

Unambiguous discrimination of high harmonic generation mechanisms in solids

Using real-space view of high harmonic generation (HHG) in solids, we develop a physically transparent and gauge-invariant approach for distinguishing intraband and interband HHG mechanisms. Our approach relies on resolving the harmonic emission according to the separation between Wannier states involved in radiative transitions. We show that the intra- and inter-band HHG emission exhibit striking qualitative differences in their dependence on this separation and can be clearly distinguished using the Wannier basis.

physics.optics↗

arXiv2025

Cross-process interference in single-cycle electron emission from metal needle tips

Though interference from different emission channels enabled a deeper understanding of strong-field photoemission in atoms and molecules, it remained out of reach for solids. Here, we explore metal needle tips under single-cycle pulses via classical trajectories extended by quantum diffusion and interference and numerical solution of the time-dependent Schrödinger equation. We find interference of direct and backscattered electrons with fringe pattern encoding sub-cycle information on birth times and near-field driven acceleration dynamics, opening routes for ultrafast solid-state metrology.

physics.optics↗

arXiv2024

Synthesis of single-cycle pulses based on a Yb:KGW laser amplifier

Yb:KGW lasers have been gaining increasing importance in ultrafast and strong-field physics, but their compression to the single- and sub- cycle regime remains a challenge. Here, we utilized a dual hollow-core fiber module for the spectral broadening of Yb:KGW pulses to more than 3.5 optical octaves, from the short-wave infrared (~1900 nm) to vacuum ultraviolet (~170 nm). A light-field-synthesizer compressed a large portion of this bandwidth (380-1000 nm) to single-cycle pulses for the first time, based on Yb:KGW technology. Our work opens the door to attaining new regimes of control and temporal compression of light pulses and their advanced applications in ultrafast spectroscopy.

physics.optics↗

arXiv2012

Theory of Attosecond Transient Absorption Spectroscopy of Krypton for Overlapping Pump and Probe Pulses

We present the first fully ab initio calculations for attosecond transient absorption spectroscopy of atomic krypton with overlapping pump and probe pulses. Within the time-dependent configuration interaction singles (TDCIS) approach, we describe the pump step (strong-field ionization using a near-infrared pulse) as well as the probe step (resonant electron excitation using an extreme- ultraviolet pulse) from first principles. We extent our TDCIS model and account for the spin-orbit splitting of the occupied orbitals. We discuss the spectral features seen in a recent attosecond transient absorption experiment [A. Wirth et al., Science 334, 195 (2011)]. Our results support the concept that the transient absorption signal can be directly related to the instantaneous hole population even during the ionizing pump pulse. Furthermore, we find strong deformations in the absorption lines when the overlap of pump and probe pulses is maximum. These deformations can be described by relative phase shifts in the oscillating ionic dipole. We discuss possible mechanisms contributing to these phase shifts. Our finding suggests that the non-perturbative laser dressing of the entire N -electron wave function is the main contributor.

physics.atom-ph↗