Related Experiment Video
Updated: Jun 5, 2026
08:01
Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
Localized whistlers in magnetized spin quantum plasmas
A P Misra1, G Brodin, M Marklund
1Department of Physics, Umeå University, SE-90187 Umeå, Sweden. apmisra@visva-bharati.ac.in
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|January 15, 2011
Summary
Investigating quantum plasma, this study reveals how electron-cyclotron waves create large-scale density fluctuations. These findings are crucial for understanding magnetized plasmas and laser-plasma interactions.
Area of Science:
- Plasma Physics
- Quantum Mechanics
- Electromagnetism
Background:
- Electron-cyclotron waves (whistlers) exhibit nonlinear propagation in magnetized plasmas.
- Quantum effects, including electron spin, significantly influence plasma behavior.
- Ion-acoustic density perturbations can modulate wave propagation.
Purpose of the Study:
- To investigate the nonlinear propagation and modulation of electron-cyclotron waves in a quantum plasma.
- To analyze the role of quantum force (Bohm potential) and ponderomotive forces (classical and spin-induced) on plasma density.
- To determine the conditions and growth rates for modulational instability.
Main Methods:
- Theoretical analysis of nonlinear wave propagation in a uniform quantum plasma.
- Inclusion of Bohm potential and classical/spin-induced ponderomotive forces.
- Derivation of modified nonlinear Schrödinger-Boussinesq-like equations.
- Numerical simulations to observe density fluctuations and modulational instability.
Main Results:
- The study derives modified nonlinear equations governing coupled wave modes.
- Exact solutions in the form of stationary localized envelopes are found.
- Numerical simulations show localized whistlers self-consistently generate large-scale density fluctuations.
- Conditions and growth rates for modulational instability are determined.
Conclusions:
- Localized electron-cyclotron waves in quantum plasmas can induce significant density fluctuations.
- The findings are relevant for strongly magnetized, dense plasmas.
- Potential applications exist in next-generation laser-solid density plasma interaction experiments.
Related Concept Videos
01:23Atomic Nuclei: Nuclear Relaxation Processes
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...
01:05Atomic Nuclei: Magnetic Resonance
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
01:03Atomic Nuclei: Nuclear Spin State Overview
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
01:23Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
01:28Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by: