Related Experiment Video
Updated: Jan 1, 2026
08:51
Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
Published on: August 18, 2017
10.8K
Attosecond Molecular Angular Streaking with All-Ionic Fragments Detection.
Wei Quan1,2, Vladislav V Serov3, MingZheng Wei1
1State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
Physical Review Letters
|December 24, 2019
Summary
This study introduces a new attosecond angular streaking method for molecules, using ionic fragments to measure electron dynamics and revealing a tunneling time under 10 attoseconds in H2.
Area of Science:
- Quantum dynamics
- Strong-field physics
- Molecular spectroscopy
Background:
- Attosecond angular streaking (attoclock) probes ultrafast electron dynamics.
- Current attoclock methods are limited to atomic targets and photoelectron measurements.
Purpose of the Study:
- To develop a novel attosecond angular streaking scheme for molecular targets.
- To measure electron tunneling times in molecules using ionic fragments.
Main Methods:
- Proposed a new attosecond angular streaking scheme using ionic fragments from dissociative ionization.
- Detected ionic fragments in the polarization plane of circularly polarized laser light.
- Performed measurements on the H2 molecule.
Main Results:
- Ionic attoclock measurements were consistent with time-dependent Schrödinger equation calculations.
- An upper bound of 10 attoseconds was determined for the tunneling time in H2.
- This tunneling time is significantly shorter than previously reported values.
Conclusions:
- The novel ionic attoclock technique is applicable to molecular systems.
- The study provides new insights into ultrafast electron dynamics and tunneling times in molecules.
Related Concept Videos
01:20Mass Spectrometry: Molecular Fragmentation Overview
5.3K
The ionization of a molecule into a molecular ion inside the mass spectrometer causes instability in the molecule's structure due to the loss of an electron. This eventually leads to the fragmentation or breaking of some bonds in the molecule. The fragmentation occurs predominantly at specific bonds to yield relatively stable fragments.
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
5.3K
01:25Atomic Absorption Spectroscopy: Atomization Methods
1.3K
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the...
1.3K
01:24Mass Spectrum: Interpretation
2.6K
An unknown compound can be established by identifying the molecular ion peak in the mass spectrum. The molecular ion peak is often weak or absent due to the predominance of fragmentation in high-energy electron beams. In such cases, a soft-energy electron beam can be used to scan the spectrum to enhance the intensity of the molecular ion peak. Additionally, chemical ionization, field ionization, and desorption ionization spectra are used to obtain a relatively intense molecular ion peak.To...
2.6K
01:16Mass Spectrometers
8.1K
This lesson details the instrumentation of a mass spectrometer—a physical instrument to perform mass spectrometry on analyte molecules and record the characteristic mass spectra. This is achieved via three chief functions:
8.1K
01:23Atomic Spectroscopy: Absorption, Emission, and Fluorescence
2.4K
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
2.4K
01:21Tandem Mass Spectrometry
2.2K
Tandem mass spectrometry is a technique that uses multiple mass analyzers in series to obtain a higher selectivity and reduce chemical noise during analyte detection. Instruments with multiple analyzers separated by an interaction cell enable secondary fragmentation and selected study of the fragment ions.Secondary fragmentations occur in the interaction cell and can be induced by various factors. Fragmentation induced by collision with inert gases, such as N2, Ar, He, etc., is called...
2.2K