We demonstrate a quantum stroboscope based on a sequence of identical attosecond pulses that are used to release electrons into a strong infrared (IR) laser field exactly once per laser cycle. The resulting electron momentum distributions are recorded as a function of time delay between the IR laser and the attosecond pulse train using a velocity map imaging spectrometer. Because our train of attosecond pulses creates a train of identical electron wave packets, a single ionization event can be studied stroboscopically. This technique has enabled us to image the coherent electron scattering that takes place when the IR field is sufficiently strong to reverse the initial direction of the electron motion causing it to rescatter from its parent ion.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.100.073003 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Lattice Anisotropy-Driven Reduction of Phonon Velocities in Black Phosphorus.
ACS Nano
January 2025
James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States.
Phonon dynamics and transport determine how heat is utilized and dissipated in materials. In 2D systems for optoelectronics and thermoelectrics, the impact of nanoscale material structure on phonon propagation is central to controlling thermal conduction. Here, we directly observe in-plane coherent acoustic phonon propagation in black phosphorus (BP) using ultrafast electron microscopy.
View Article and Find Full Text PDFMagnetophononics and the chiral phonon misnomer.
PNAS Nexus
January 2025
The Harrison M. Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI 48109-1040, USA.
The direct, ultrafast excitation of polar phonons with electromagnetic radiation is a potent strategy for controlling the properties of a wide range of materials, particularly in the context of influencing their magnetic behavior. Here, we show that, contrary to common perception, the origin of phonon-induced magnetic activity does not stem from the Maxwellian fields resulting from the motion of the ions themselves or the effect their motion exerts on the electron subsystem. Through the mechanism of electron-phonon coupling, a coherent state of circularly polarized phonons generates substantial non-Maxwellian fields that disrupt time-reversal symmetry, effectively emulating the behavior of authentic magnetic fields.
View Article and Find Full Text PDFElectronic dynamics created at conical intersections and its dephasing in aqueous solution.
Nat Phys
November 2024
Laboratory of Physical Chemistry, ETH Zürich, Zurich, Switzerland.
A dynamical rearrangement in the electronic structure of a molecule can be driven by different phenomena, including nuclear motion, electronic coherence or electron correlation. Recording such electronic dynamics and identifying its fate in an aqueous solution has remained a challenge. Here, we reveal the electronic dynamics induced by electronic relaxation through conical intersections in both isolated and solvated pyrazine molecules using X-ray spectroscopy.
View Article and Find Full Text PDFDirect quantification of the plasmon dephasing time in ensembles of gold nanorods through two-dimensional electronic spectroscopy.
Nanoscale Adv
January 2025
Department of Chemical Sciences, University of Padova via Marzolo 1 35131 Padova Italy
In this study, we used two-dimensional electronic spectroscopy to examine the early femtosecond dynamics of suspensions of colloidal gold nanorods with different aspect ratios. In all samples, the signal distribution in the 2D maps at this timescale shows a distinctive dispersive behavior, which can be explained by the interference between the exciting field and the field produced on the nanoparticle's surface by the collective motion of electrons when the plasmon is excited. Studying this interference effect, which is active only until the plasmon has been dephased, allows for a direct estimation of the dephasing time of the plasmon of an ensemble of colloidal particles.
View Article and Find Full Text PDFCoherent Photocurrent Injection through Quantum Interference between Stimulated Electronic Raman Scattering and Single-Photon Absorption in Intrinsic Graphene.
ACS Nano
January 2025
Center for Terahertz Waves and School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China.
The physical picture for photocurrent injection and coherent control in intrinsic graphene under two-color laser excitation remains obscure. Previously, photocurrent injection of intrinsic graphene was attributed to the quantum interference between two electronic transition pathways of single-photon and two-photon absorptions as well as layer-to-layer coupling. Here, we show that quantum interference between stimulated electronic Raman scattering and single-photon absorption plays a very important role in contributing to the total photocurrent, while interlayer coupling does not sufficiently affect the photocurrent injection, which is in contrast to the previous interpretation of the experimental results on photocurrent injection and coherent control.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!