Related Experiment Video
Updated: Jan 30, 2026

06:37
Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
5.1K
Ehrenfest+R dynamics. I. A mixed quantum-classical electrodynamics simulation of spontaneous emission
Hsing-Ta Chen1, Tao E Li1, Maxim Sukharev2
1Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
The Journal of Chemical Physics
|February 3, 2019
Summary
This study explores quantum-classical theory for electron-photon interactions. A new Ehrenfest+R method accurately models spontaneous emission and distinguishes field fluctuations.
Area of Science:
- Quantum dynamics
- Computational physics
- Electromagnetism
Background:
- Investigating quantum systems interacting with electromagnetic fields is crucial.
- Existing mixed quantum-classical theories have limitations in accurately describing photon field dynamics.
Purpose of the Study:
- To develop a more accurate theoretical framework for electron-photon interactions.
- To improve the modeling of quantum features in the photon field.
- To capture spontaneous emission and differentiate field types.
Main Methods:
- Utilized mixed quantum-classical theory.
- Compared classical path approximation with Ehrenfest dynamics.
- Introduced a novel Ehrenfest+R method.
- Employed coupled Maxwell-Liouville equations.
Main Results:
- Ehrenfest dynamics show limitations in capturing photon field quantum features.
- The Ehrenfest+R method successfully recovers spontaneous emission.
- The new method distinguishes between electromagnetic fluctuations and coherent emission.
Conclusions:
- The Ehrenfest+R method offers a significant advancement in simulating quantum-classical systems.
- This approach provides a more complete description of electron-photon interactions.
- Accurate modeling of spontaneous emission is now achievable.
Related Concept Videos
Quantum Numbers
50.0K
It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.
50.0K
Emission Spectra
76.2K
When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a range of energies, and thereby produce a continuous spectrum in which an unbroken series of wavelengths is present.
76.2K
Spontaneity
29.8K
A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is “driven” by the continual input of energy from an external source. Processes have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill (spontaneous process), but uphill flow (nonspontaneous process) requires outside intervention such as the use of a pump. Iron exposed to...
29.8K
The Quantum-Mechanical Model of an Atom
57.2K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
57.2K
Classical Conditioning
2.2K
Associative learning, a core principle in behavioral psychology, involves forming connections between events and facilitating learned responses. This concept is vividly illustrated by classical conditioning, a process extensively studied by the Russian physiologist Ivan Pavlov. Pavlov's pioneering research on dogs' digestive systems led to the discovery that behaviors can be learned through association, laying the groundwork for classical conditioning.
Ivan Pavlov observed that dogs...
Ivan Pavlov observed that dogs...
2.2K
Principles of Classical Conditioning
1.8K
Classical conditioning, as described by Ivan Pavlov, is a foundational concept in associative learning, where a neutral stimulus becomes capable of eliciting a conditioned response through association with an unconditioned stimulus. The process of acquisition, where this learning occurs, and the subsequent phenomena of contiguity, contingency, generalization, discrimination, extinction, and spontaneous recovery are crucial for a comprehensive understanding of classical conditioning.
During the...
During the...
1.8K

