I did my M.SC in one of the High energy physics experiments looking for "natural" magnetic monopole but now moved for supersymmetry then flavor physics.
The title is basically clickbait and personally it triggers a collective truma of hundreds who worked on that during the last 7 decades. Well we might actually have discovered a magnetic monopole in the 80s on the famous valentine's day experiment/incident. [1]
As many people here mentioned, these are not the groundbreaking and fundamental particles that we call magnetic monopole that was predicted by Dirac or GUT monopole (predicted by many grand unification theories). This manifestation of spin effects is consistent with the unsymmetric Maxwell's equations we have and wouldn't prompt a modification like if we discovered the "fundamental" magnetic monopole. Well thanks to inflation, we probably never going to be able to see it even it exists. [2]
Probably titles like these are part of the reason why HEP physicists have their own APS conference (april) and don't participate in the more generic march conference /S.
Reminds me of how you occasionally get a "GRAD STUDENTS BREAK SPEED OF LIGHT" article and it turns out they just shined a laser on the moon and turned it really fast or something.
Good question, the short answer is no. For the long answer, let's begin by simplifying the concept of the Standard Model itself.
The Standard Model is a theory that describes the fundamental particles and forces (except gravity) in the universe. It is essentially a set of mathematical equations that explain how particles like quarks and leptons (i.e electrons) interact through forces mediated by particles like photons (for electromagnetic force), W and Z bosons (for weak nuclear force), and gluons (for strong nuclear force). These interactions are described using quantum field theory, which combines quantum mechanics (dealing with the smallest scales of energy levels and particles) with special relativity (dealing with particles moving at high speeds).
Now, regarding magnetic monopoles, these are hypothetical particles proposed in various theories. There are two main types of hypothetical magnetic monopoles that theorists have considered:
- Dirac Monopoles: Proposed by Dirac in 1929, these monopoles are simpler and would arise from modifications to electromagnetism. Dirac showed that if magnetic monopoles exist, they would explain why electric charge is quantized (i.e., why it comes in discrete amounts like the charge of an electron). However, Dirac monopoles don't fit neatly into the Standard Model as it currently stands. They would require some extension or modification of the model.
- Grand Unified Theory (GUT) Monopoles: These are more complex and emerge from grand unified theories, which are theoretical frameworks that attempt to unify the gravity, electromagnetic, weak, and strong forces into a single force. In these theories, monopoles are heavy and rare relics from the early universe, a time when the fundamental forces were unified. In many GUTs, conditions in the early universe would have allowed for the creation of magnetic monopoles. These monopoles are predicted to be very massive and thus difficult to produce and detect with current technology (LHC energies are still too low to produce them).
So as of now, there is no experimental evidence for magnetic monopoles (this did not change by this announcement). Their theoretical existence is a topic of significant interest, but it remains speculative and outside the direct scope of the Standard Model. Any confirmation of magnetic monopoles would be groundbreaking, potentially opening up new physics beyond the Standard Model.
Ok… this still needs to be duplicated, but if it is confirmed it is somewhat of a big deal.
They’re not “real” monopoles, in the sense of individual particles that generate a divergent field but rather a quasi-particle (the collective behavior of many individual atoms producing this overall effect).
In the worlds of the authors:
“These monopoles are a collective state of many spins that twirl around a singularity rather than a single fixed particle, so they emerge through many-body interactions. The result is a tiny, localised stable particle with diverging magnetic field coming out of it,” said co-first author Dr Hariom Jani, from the University of Oxford.
That being said, the applications are still pretty exciting and this is something that many people wouldn’t have tought possible at all.
This is 2d monopoles on the 2d surface of a material.
This is equivalent to propping up a horseshoe magnet with the ends up, and laying a piece of paper across it; that also gives you a 2d surface with a pair of monopoles on it.
It's still interesting and probably useful for building things, but it's not "we broke a known law of physics".
I don't think the paper cares, since it's about how the fields on the surface behave locally while the other pole needing to exist (and of course it could be split into multiple weaker ones, or smeared out, or whatever) is an invariant that applies to the object as a whole.
> They’re not “real” monopoles, in the sense of individual particles that generate a divergent field but rather a quasi-particle (the collective behavior of many individual atoms producing this overall effect).
Can this be replicated on the macro scale with meta materials?
Perpetual motion machine. Make a ring of monopoles all facing one direction along the circumference of the ring. Put a 2nd ring of opposing monopoles inside facing the opposite direction along the ring.
Stupid question. If you develop a quasi-particle monopole, which I guess is something that is not a monopole but behaves like one, can you use it in such a configuration and get the behaviour you are describing?
It's a quasi-particle that's a monopole, and I think they've found quasi-particles that behaved as monopoles before if I'm not mistaken? In more exotic materials than hematite, though, I think.
> Using muon spin rotation as a suitable local probe, we apply the method to a real material, the ‘spin ice’ Dy2Ti2O7 (refs 5–8). Our experimental measurements prove that magnetic charges exist in this material, interact via a Coulomb potential, and have measurable currents.
> The reported duality between magnetic charges and topological AFM textures sheds light on a new class of materials hosting 2D monopolar physics in contrast with other systems that harbour emergent magnetic monopoles, such as the pyrochlore spin ice. Although intriguing, monopoles in spin ice are intrinsically distinct, as they have an underlying gauge charge, which is topological and quantized. Conversely, the emergent magnetic charges in haematite are 2D, not quantized and are topological in the sense that they dress topological AFM textures underpinning them.
"""this is the first time we’ve actually seen a __two-dimensional__ monopole in a naturally occurring magnet ...
These monopoles are a collective state of many spins that twirl around a singularity rather than a single fixed particle, so they emerge through many-body interactions. The result is a tiny, localised stable particle with diverging magnetic field coming out of it,"""
So do I take it that there is some kind of superposition of spins that locally, possibly just in a 2D cross section, appears to have a magnetic field with non-zero divergence? Is \nabla\cdot\vec{B} actually violated somewhere? The language seems pretty cagey.
Incidentally, I belive Dirac posited that they existence of magnetic monopoles would explain the quantization of charge.
In the "Emergent Magnetic Charge" section, second paragraph:
"Finally, we emphasize that the observation of emergent monopoles is fully consistent with the modelling of AFM topological textures in Fig. 2 and does not violate Maxwell’s equation as they are, in fact, sinks and sources of the H^ field."
So this is a collective effect of a bunch of magnetic dipoles, and they go on to describe how div B is indeed zero in the material.
(not a physicist) Dirac proposed a sufficiently long and narrow solenoid would behave as if each end was a magnetic monopole. If the math says it works, then it should be possible in nature.
Please correct my understanding if you know better and I'm wrong.
From Protector, by Larry Niven.
Published by Del Rey in 1973
"Nick Sohl was coming home.
...He had gone mining in Saturn's rings, with a singleship around him and a shovel in his hand (for the magnets used to pull monopoles from asteroidal iron did look remarkably like shovels)...
A century ago monopoles had been mere theory and conflicting theory at that. Magnetic theory said that a north magnetic pole could not exist apart from a south magnetic pole, and vice-versa. Quantum theory implied that they might exist independently.
The first permanent settlements had been blooming among the biggest Belt asteroids when an exploring team found monopoles scattered through the nickel-iron core of an asteroid. Today they were not theory, but a thriving Belt industry. A magnetic field generated by monopoles acts in an inverse linear relationship rather than an inverse-square. In practical terms, a monopole-based motor or instrument will reach much further. Monopoles were valuable where weight was a factor, and in the Belt weight was always a factor. But monopole mining was still a one man operation.
Nick's luck had been poor. Saturn's rings were not a good region for monopoles anyway; too much ice, too little metal. The electromagnetic field around his cargo box probably held no more than two full shovelfuls of north magnetic pole. Not much of a catch for a couple weeks backbreaking labor... but still worth good money at Ceres."
The math is slightly incorrect. Magnetic field strength falls of with the cube of distance rather than square. For magnetic (or electric) monopoles, the inverse square law applies.
A lot of people are making a point of the "quasi-particle vs particle" distinction. Other than an actual monopole particle being a never-before observed thing, would there be any actual difference in the use and application of a monopole particle vs a monopole quasi-particle?
In other words, should we expect that this discovery (and the apparently previously discovered monopole quasiparticles) have the exact same use and application as a hypothetical normal particle monopole?
Well, my understanding is that some theories of physics predict the existence of monopoles, and some say they can't exist. Finding a real monopole would have an impact on our understanding of physical reality, whereas this is more like an incredibly impressive engineering achievement right? (I could be misunderstanding what the researchers have done)
They are very different. These are just emergent magnetic charge distributions in certain materials. Real north and south particles would be like magnetic ions. Really weird batteries and magnetic circuits would become possible.
In the "Emergent Magnetic Charge" section, second paragraph:
"Finally, we emphasize that the observation of emergent monopoles is fully consistent with the modelling of AFM topological textures in Fig. 2 and does not violate Maxwell’s equation as they are, in fact, sinks and sources of the H^ field."
So this is a collective effect of a bunch of magnetic dipoles, and they go on to describe how div B is indeed zero in the material.
It is not possible for a group of particles to have a divergent field when none of the individual particles have a divergent field.
This is not less interesting because it's "just a quasi-particle".
This is 2d surface behavior of a solid material. The magnetic fields on the 2d surface act as if there are mobile particles with magnetic charge moving around on the surface.
That's a good instinct to have. The answer is that quasiparticles can cover a multitude of sins. My personal Four Horsemen are:
-Quasiparticles: We select some property by drawing a box around a set of adjacent particles and computing over those particles. That property is not represented in a single and unattached member of that box. It isn't the real thing but might approximate some nifty functions you wanted if scaled up and embedded in the right material under the correct circumstances.
-"...in a simulation": This means that this is only as good as your programming (and databases and libraries) is, on top of how well that programming relates to the math you think represents the system in question. Not only do you not have the real thing, you have bits representing the answer to your imperfect programming based on what you think the math is (and what math can be ignored) in your model.
-Analogue of in another system: See sonic black holes. Parallels are drawn between math in one system and math is an entirely different system. Some expect that new inferences can be drawn from the comparison, but you still don't have the real thing, you have a cardboard box with subdividers and you wonder how that applies to high-rises.
-Property exists in n-dimensions: Where N is not our three spatial dimensions. It's not the real thing because we don't have anything with just two spatial dimensions, or an extra spatial dimension, but maybe, just maybe, that can lead to some interesting properties on the edge of the thing, or its face, but probably not in the way you would expect.
Listen for their hooves during any breathless science press release about physics, materials science, and so on.
Since you appear to be asking in good faith, despite this being a frankly irrationally hostile environment whenever the subject comes up, I’ll answer.
The raw data shows no warming trend. NOAA and NASA admit this, it’s not a conspiracy theory. The adjustments made that show warming are based on models. Hence to trust the warming trend you have to trust the models, which are very computer simulations.
In a different perspective, the magnetic field itself is a result of special relativity. The magnetic field is an alternative way to explain electromagnetism without citing special relativity. (Or to say, electrostatic field and special relativity are sufficient to explain everything in electromagnetism, the existence of magnetic field is unnecessary.)
If the existence of magnetic field is unnecessary, there is no reason to even search for a magnetic monopole.
I maintain nonetheless that yin-yang dualism can be overcome. With sufficient enlightenment we can give substance to any distinction: mind without body, north without south, pleasure without pain. Remember, enlightenment is a function of willpower, not of physical strength.
Essentially, it's a configuration of 2 south poles and 2 north poles. It's pretty important if you're doing quantitative magnetism. Many magnetic configurations don't generate a pure dipole-like field, but also need higher order contributions - like quadrupole and octopole moment - if you want to model/calculate the field.
Quadrupoles also have useful technical properties, you can use one to re-focus the beam in a particle accelerator, for example. In a sense, they act like magnetic lenses.
Thanks. I looked at that, but I don't have the maths background to follow the real explanation. I get the four bar magnets or four coils stuck together, as an example of the charge state, but that looks simplified to the point that it's maybe not real. I think I'm trying to bridge a gap in my understanding between "this is a convenient way to refer to a complex interaction between multiple magnetic fields", and "this is a object (constructed? naturally occurring?) that I can hold in my hand".
Or, maybe that's not even a reasonable mental model / distinction - magnetics be freaky.
If true, I assume there is a quantum of magnetic... "charge"? E.g. something like h_bar*e? (Sorry, I could go away and figure out the correct units here, but I haven't bothered...)
The title is basically clickbait and personally it triggers a collective truma of hundreds who worked on that during the last 7 decades. Well we might actually have discovered a magnetic monopole in the 80s on the famous valentine's day experiment/incident. [1]
As many people here mentioned, these are not the groundbreaking and fundamental particles that we call magnetic monopole that was predicted by Dirac or GUT monopole (predicted by many grand unification theories). This manifestation of spin effects is consistent with the unsymmetric Maxwell's equations we have and wouldn't prompt a modification like if we discovered the "fundamental" magnetic monopole. Well thanks to inflation, we probably never going to be able to see it even it exists. [2]
Probably titles like these are part of the reason why HEP physicists have their own APS conference (april) and don't participate in the more generic march conference /S.
[1]https://www.nature.com/articles/429010a
[2] https://en.m.wikipedia.org/wiki/Big_Bang#Magnetic_monopoles