scholarly journals Vortices as fractons

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Darshil Doshi ◽  
Andrey Gromov

AbstractFracton phases of matter feature local excitations with restricted mobility. Despite the substantial theoretical progress they lack conclusive experimental evidence. We discuss a simple and experimentally available realization of fracton physics. We note that superfluid vortices form a Hamiltonian system that conserves total dipole moment and trace of the quadrupole moment of vorticity; thereby establishing a relation to a traceless scalar charge theory in two spatial dimensions. Next we consider the limit where the number of vortices is large and show that emergent vortex hydrodynamics also conserves these moments. Finally, we show that on curved surfaces, the motion of vortices and that of fractons agree; thereby opening a route to experimental study of the interplay between fracton physics and curved space. Our conclusions also apply to charged particles in a strong magnetic field.

2021 ◽  
Vol 2059 (1) ◽  
pp. 012014
Author(s):  
S A Martsinukov ◽  
D K Kostrin

Abstract The paper presents an experimental verification of the adequacy of a physical and mathematical model describing the influence of an external transverse magnetic field on the distribution of the charged particles in a positive column of a gas discharge. A gas-discharge laser located in a transverse magnetic field was used to conduct the study. The vacuum installation allows pumping out the system and feeding the gas mixture into it under a certain pressure. The data obtained during the experiments differ from the calculated ones by no more than 4–5 %.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1870
Author(s):  
Dmitry Borin ◽  
Robert Müller ◽  
Stefan Odenbach

This paper presents the results of an experimental study of the influence of an external magnetic field on the shear flow behaviour of a magnetic fluid based on barium hexaferrite nanoplates. With the use of rheometry, the magnetoviscosity and field-dependent yield-stress in the fluid are evaluated. The observed fluid behaviour is compared to that of ferrofluids with magnetic nanoparticles having high dipole interaction. The results obtained supplement the so-far poorly studied topic of the influence of magnetic nanoparticles’ shape on magnetoviscous effects. It is concluded that the parameter determining the observed magnetoviscous effects in the fluid under study is the ratio V2/l3, where V is the volume of the nanoparticle and l is the size of the nanoparticle in the direction corresponding to its orientation in the externally applied magnetic field.


1958 ◽  
Vol 6 ◽  
pp. 446-447
Author(s):  
Willard H. Bennett

A tube has been developed in which the shapes of streams of charged particles moving in the earth's magnetic field can be produced accurately to scale. The tube has been named the Störmertron in honor of Carl Störmer who calculated many such orbits. New developments which have made this tube possible include a method for coating the inside of large glass tubes with a transparent electrically conducting film, and an electron gun producing gas-focused streams in less than ½ micron of mercury vapor, a nearly vapor-free grease joint, and a nearly vapor-free carbon black. The magnetic dipole field of the earth is simulated with an Alnico magnet capped with properly shaped soft iron caps. The stream is deflected using two pairs of yoke coils near the gun.


Sign in / Sign up

Export Citation Format

Share Document