Physics Monopole-y: A Key to a Unified Theory of Everything?

By Aubrielle Hvolboll

Eighty-six years ago, physicist Paul Dirac theorized the existence of magnetic monopoles; that is, magnet poles that exist independent of each other. Not north and south together. North. And south. Separately.

Nearly a century later, Felix Flicker, a Berkeley theoretical physicist and post-doctoral researcher in the lab of Norman Yao, is working to help prove Dirac’s theory. “There was this sort of philosophical point I was thinking of,” Flicker says. “You can’t have the left end of a stick without the right end, can you?”

Even when broken down to nanometer-sized particles, one fact remains about magnets: North and south poles are invariably found together. “A magnet is called a magnetic dipole,” Flicker explains. “As in, it’s got two poles, a north and a south,” which cannot be separated. As in a bar magnet. But, he goes on to explain, there is an electric dipole, which has “an electron and a positron” at opposite poles. As in a battery.

Finding magnetic monopoles would help physicists achieve a unified theory of the universe. “All the laws of nature would look a lot nicer if they did exist…. It’s just that we’ve never found the things.”

Why is this phenomenon considered an oddity of physics? “With the electric dipoles, you’re allowed to just pull them apart and you’ve got the two separate charges. For some reason in the magnetic case, you can’t pull them apart,” he says. “Why does it exist as a dipole and not as two monopoles?”

Electricity and magnetism are so closely related that electromagnetism—their interaction—is one of the four fundamental forces of our universe. The only dissimilarity between electricity and magnetism seems to be the existence of electric monopoles—commonly known as charged particles—and the absence of magnetic monopoles. Finding magnetic monopoles would reconcile the two and help physicists achieve a unified theory of the universe.

“All the laws of nature would look a lot nicer if they did exist…. It’s just that we’ve never found the things,” Flicker says.

Lab experiments have produced monopole-like structures, but so far, no one has seen anything more than a simulation. Now, though, with a new detector, ultracold temperatures, and a bit of luck, Flicker and his colleagues may finally be able to observe this phenomenon in a magnetic crystalline material called “spin ice.”

The spin ice in question, an intricate molecular lattice, is grown in Oxford and was sent to Harvard’s NV-magnetometer, one of the few devices equipped to handle the proposed experiment. Run by Harvard’s condensed matter physicist Amir Yacoby, the device has been created to withstand temperatures as cold as 1.5 kelvin, which is about –271.65 degrees Celsius—really, really cold.

The NV-magnetometer relies on individual defects in diamond to scan magnetic fields; it will scan an area of spin ice 10 x 10 nanometers (1 nanometer = one-billionth of a meter) and, if all goes as planned, will record a magnetic monopole pass through in milliseconds.

Flicker says that, if successful, the findings will be the “smoking gun signature” for the magnetic monopole phenomenon. Though not an observation of a new fundamental particle predicted by Dirac, this may get as close to spotting one as scientists ever come.

Magnetic monopole particles are likely extremely rare; Flicker speculates there may be a single particle in every galaxy. In the case of Flicker’s experiment, this will not constitute the observation of a real particle.

“Whenever a particle is detected, it is interacting with the detection apparatus and therefore not fundamental in the strict sense. It’s a quasiparticle, in a loose sense of the word,” he explains. “Of course, we can infer the existence of fundamental particles even if we’ll never see them. Like inferring the existence of an objective universe, even though all our experiences of it are subjective.”

Practical uses of magnetic monopoles are tricky. As can often be the case with physics, not every discovery has a straightforward practical application. Flicker has a few speculations for monopole use: “magnetricity” and computer memory. If magnetic monopoles can wander through spin ice, then they may be able to flow like electrons in an electric current and be harnessed the same way we harness electricity. Magnetricity could potentially be used as a much more compact form of computer memory.

“But these are pretty early stages,” Flicker says. “We’ve got to prove this thing exists. Then hopefully people will get much more interested in trying to implement it in technology.”

From the Fall 2017 Bugged issue of California.
Filed under: Science + Health
Image source: Aubrielle Hbvolboll
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A two switches (bits) is a unipole analog
Magnetic monopoles will never be discovered because the the understanding of magnetic fields is completely inaccurate to begin with. The magnetic field surrounding a common bar magnet does not move in a direction from the “north end to the south end of the magnet” as currently understood. Instead, the magnetic field surrounding a common bar magnet moves in two opposite directions from the center of the magnet. So, there is a north magnetic field component, and a south magnetic field component to the bar magnet. I firmly believe the idea also applies to the the understanding of “electric dipoles.” So, for any “separation of charges” within an electric dipole there is actually an opposite magnetic component within the separated charge.
Also, to extend on this, the very fact that you can not break a magnet in half and have a single north pole and a single south pole. As it is well know that the broken parts will just be a new, smaller, dipole. Based on this, it tells me that for every structure to the universe there are at least two components to them. I think this applies to the atom as well, as the understanding of the atom is not fully accurate either in my opinion. I do not agree that electrons orbit around a nucleus that carries positive and neutral charges. Instead the atom is most likely comprised of solid matter surrounded by an electromagnetic field that has two parts to it.
Hello, I do not believe there are magnetic monopoles. However, I do believe the neutrino is a magnetic point charge. Anyone interested can find my cranky books on the internet!
Just as a historical note, I recall back in the late 70s a team of astrophysicists at Berkeley made the news declaring they had found evidence of the monopole. Shortly thereafter, a retraction was offered.