Quantization of magnetic flux
going through superconducting ring is explained that along this loop, quantum phase (order parameter in this case) has to return to the initial phase, so it makes integer number of full rotations - this number determines the total magnetic flux going through this loop, like on this picture:
There appears natural question - why we couldn't take this argument into just a loop in vacuum?
In static picture, we should be able to decrease such abstract loop down to having single flux quant going through it and so they seem to be physical lines in space.
These natural consequences of quantum mechanics are called 'vortex lines'
by prof. Bialynicki-Birula (well known in Poland).
Very similar concepts are popular in considerations of corona plasma
of our Sun.
There is generally a problem for standard MHD models to explain that while the surface has thousands of kelvins, for corona it exceeds million kelvins ('coronal heating problem
'). The hope could be the observed magnetic flux ropes
with such explanation, or different Physorg news
, sometimes called nanoflares
) - charged particles instead of just repelling each other, gathers in nearly one-dimensional objects along magnetic lines, which carries very large energy released mainly while magnetic reconnections
Such lines should have large energy density per length, so in low temperatures we could expect them rather only in microscopic scales. Quantum rotation operator suggests that such lines should go through fermions along their spin axis - it could explain their tendency to couple (electrons in orbitals, Cooper pairs, nucleons in nuclei), but also suggests how optical photons looks like: topology says that to destroy such couple for e.g. deexcitation, we should twist one of them 180 deg - changing its spin by 1: like from 1/2 to -1/2.
Such twist is angular acceleration then deceleration - angular momentum conservation suggests that there should be created kind of EM wave 'carrying this 180deg rotation' ('have spin 1'), it could also help destabilizing other excited couples (stimulated emission) - we get optical photon candidate:
Accepting such 1D structures also allows for other particle-like constructs, for example if on such vortex line there would be additional 'rotation toward the center of line', it would get charge and it would change it into opposite vortex line (became magnetic dipole) - we would get lepton-like construct (pictures
Could (some?) magnetic flux lines be physical objects?
Is something like corona's magnetic flux ropes observed also in plasma experiments like polywell - that against Coulomb repulsion, charged particles have tendency to gather on lines along magnetic field?
Would it affect its stability?