Related Experiment Video
Updated: Mar 10, 2026
06:53
Scanning SQUID Study of Vortex Manipulation by Local Contact
Published on: February 1, 2017
7.4K
Vortex Pinning and Dynamics in the Neutron Star Crust
Gabriel Wlazłowski1,2, Kazuyuki Sekizawa1, Piotr Magierski1,2
1Faculty of Physics, Warsaw University of Technology, Ulica Koszykowa 75, 00-662 Warsaw, POLAND.
Physical Review Letters
|December 17, 2016
Summary
Superfluid vortices in neutron stars repel nuclear defects in the crust. This interaction, crucial for understanding star glitches, was simulated using a novel approach to analyze vortex dynamics.
Area of Science:
- Astrophysics
- Nuclear Physics
- Condensed Matter Physics
Background:
- The interaction between superfluid vortices and the neutron star crust is a long-standing question.
- This interaction is conjectured to be responsible for vortex creep and glitches in neutron stars.
- Anderson and Itoh first proposed this interaction in 1975.
Purpose of the Study:
- To investigate the dynamics of superfluid vortices interacting with nuclear defects in the neutron star crust.
- To characterize the repulsive force between vortices and nuclei.
Main Methods:
- A novel computational approach was used to simulate vortex dynamics.
- The motion of superfluid vortices in response to the presence of nuclear defects was tracked.
- The force per unit length of the vortex line was analyzed as a function of separation from the nucleus.
Main Results:
- Superfluid vortices are repelled by nuclei (nuclear defects) in the neutron star crust.
- The motion of vortices in response to nuclei is perpendicular to the applied force.
- The force characterizing the vortex-nucleus interaction was quantified based on their separation.
Conclusions:
- Nuclear defects in the neutron star crust repel superfluid vortices.
- This repulsion provides a new mechanism for understanding vortex dynamics and glitches in neutron stars.
Related Concept Videos
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.3K
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.
1.3K
03:18Nuclear Stability
23.8K
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together...
To hold positively charged protons together...
23.8K
01:28Magnetostatic Boundary Conditions
1.7K
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
1.7K
01:03Atomic Nuclei: Nuclear Spin State Overview
2.1K
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...
2.1K
01:24Potential Due to a Magnetized Object
847
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
The vector...
847
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
2.5K
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.
2.5K