A test for monopoles ?

[Selfsim]

A recently published paper (8th August in Phys Review Letters) … speaks of a test for monopoles ...
More details and easier to read:
Freezing magnetic monopoles: How dipoles become monopoles and vice versa ...

Magnetic monopoles, entities with isolated north or south magnetic poles, weren't supposed to exist. If you try to saw a bar magnet in half, all you succeed in getting are two magnets, each with a south and north pole. In recent years, however, the existence of monopoles, at least in the form of "quasiparticles" consisting of collective excitations among many atoms, has been predicted and demonstrated in the lab.

Huh ? … Where can such a thing possibly exist (in reality) ? ...

Normally all magnetic poles should be confined within two-pole couplets---the traditional magnetic dipole. However, at a low enough temperature, around 5 K, "frustration" among the magnetic atoms---they want to align with each other but can't because of the inherent geometry of the material---leads to a disordered state with strong, synchronized fluctuations. Unpaired magnetic poles can form amid this tumult. That is, particles (quasiparticle excitations, to be exact) in spin ice with a net magnetic "charge" can exist and move about. A gas of electric charges is called a "plasma," so some scientists refer to the analogous tenuous cloud of magnetic charges as a "monopole plasma."

Chuckle, chuckle is all I can say …
… (I don't want to raise the ire of a group of certain passionate 'alternative cosmologists') ..

"These kinds of magnetic monopoles are not just mathematical abstractions," said Powell. "They really appear.
...
Powell's framework for monopoles includes testable predictions about how to observe the transition from monopoles into confined poles.

'Twill be interesting to see how all this pans out .. given that inflation and flatness are a consequence of the production of monopoles in the early universe ...

Regards

[ShinAce]

Fractional charges aren't supposed to exist, but they do as a collection of particles. Doesn't mean a single free particle can have non integer charge. The fractional quantum hall effect is not proof of fractional charge.

Same with magnetism. Magnetic monopoles do not exist. 'Quasiparticle' magnetic monopoles were just a matter of time.

[cjameshuff]

...there doesn't seem to be anything there about testing for monopoles. It's not something that is difficult to do, not at all comparable to, say, neutrino detection...a conductive loop will do the job, and some very sensitive searches with SQUID devices and such have been going on for decades.

The paper looks like it's about creation of analogous quasiparticles in materials with particular magnetic properties. These "monopoles" only occur in pairs of opposite poles, each being one end of a string (as in the topological defect). The field lines going through the string have little effect on the surroundings, and so the ends of the string behave like free monopoles.