Coherent x-ray spontaneous emission spectroscopy of conical intersections
Deependra Jadoun1, Markus Kowalewski1
1Department of Physics, Stockholm University, Albanova University Centre, SE-106 91 Stockholm, Sweden.
The Journal of Chemical Physics
|March 1, 2024
Summary
This study shows how coherent spontaneous emission can detect conical intersections in molecules. These intersections are crucial for understanding ultrafast photochemical processes and excited-state decay.
Area of Science:
- Photochemistry
- Quantum Chemistry
- Spectroscopy
Background:
- Conical intersections are critical in photochemistry, leading to ultrafast radiationless decay.
- The Born-Oppenheimer approximation breaks down near conical intersections, creating complex quantum phenomena.
- Coherent superposition of electronic states is generated when molecules pass through conical intersections.
Purpose of the Study:
- To theoretically demonstrate a novel method for probing conical intersections.
- To investigate the use of coherent spontaneous emission for detecting molecular conical intersections.
- To analyze the spectral signatures of coherent superpositions generated by conical intersections.
Main Methods:
- Theoretical simulations of molecular systems exhibiting conical intersections.
- Modeling coherent spontaneous emission from ordered samples.
- Analysis of simulated emission spectra to identify signatures of electronic coherence.
Main Results:
- Coherent spontaneous emission spectra reveal clear signatures of the coherent superposition of electronic states.
- The proposed method can directly probe the occurrence of conical intersections.
- Simulation results highlight the influence of x-ray probe bandwidth on detecting these phenomena.
Conclusions:
- Coherent spontaneous emission is a viable technique for detecting conical intersections in molecules.
- This method offers a direct pathway to study nonadiabatic effects in photochemistry.
- Understanding x-ray probe requirements is essential for experimental observation.
Related Concept Videos
01:30Atomic Emission Spectroscopy: Interference
184
In atomic emission spectroscopy (AES), high-temperature atomizers excite a broad range of elements and molecules that generate complex emissions from sources such as oxides, hydroxides, and flame combustion products in the flame or plasma. Several strategies can be employed to minimize spectral interferences caused by overlapping emission lines or bands. These include increasing instrument resolution, choosing alternative emission lines, optimally placing the detector in low-background regions,...
184
01:20Atomic Emission Spectroscopy: Overview
2.1K
Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...
2.1K
01:23Atomic Spectroscopy: Absorption, Emission, and Fluorescence
908
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...
908
01:22Atomic Emission Spectroscopy: Instrumentation
391
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
391
01:29Atomic Emission Spectroscopy: Lab
161
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
161
01:12Interaction of EM Radiation with Matter: Spectroscopy
1.5K
Electromagnetic (EM) radiation can be considered an oscillating electric and magnetic field propagating through a medium that can interact with matter in its path. The electric field in the radiation can interact with electrical charges in the atoms or molecules in the matter. On the other hand, the magnetic field can interact with the magnetic field in the atomic nucleus. The study of the interaction between electromagnetic radiation and matter is termed spectroscopy. Spectroscopy is the study...
1.5K