Skip to main content

One kind of supersymmetry shown to emerge naturally

One kind of supersymmetry shown to emerge naturally
This image shows supersymmetry in a three-dimensional topological superconductor: Ising magnetic fluctuations (denoted by red arrows) at the boundary couple to the fermions (blue cone). Credit: UCSB
(Phys.org) —UC Santa Barbara physicist Tarun Grover has provided definitive mathematical evidence for supersymmetry in a condensed matter system. Sought after in the realm of subatomic particles by physicists for several decades, supersymmetry describes a unique relationship between particles.
"As yet, no one has found  in our universe, including at the Large Hadron Collider (LHC)," said the associate specialist at UCSB's Kavli Institute for Theoretical Physics (KITP). He is referring to the underground laboratory in Switzerland where the famous Higgs boson was identified in 2012. "This is a fresh insight as to how supersymmetry arises in nature." The findings of Grover's research, conducted with colleagues Donna Sheng and Ashvin Vishwanath, appear in the current online edition of the journal Science.
The fundamental constituents of matter—electrons, quarks and their relatives—are fermions. The particles associated with fundamental forces are called bosons. Several decades ago, physicists hypothesized that every type of particle in the Standard Model of particle physics, a theory that captures the dynamics of known , has one or more superpartners—other types of particles that share many of the same properties but differ in a crucial way.
If a particle is a fermion, its superpartner is a boson, and if a particle is a boson, its superpartner is a fermion. This is supersymmetry, a postulated unique theoretical symmetry of space.
While the Standard Model governing the ordinary world is not supersymmetric, it is often theorized that the more "fundamental" theory relevant to very hot systems, such as those probed in high-energy particle accelerators like the LHC (or higher energy ones yet to be built), might exhibit supersymmetry. This has yet to be proved or disproved by accelerator experiments.
However, through their calculations, Grover and his co-authors show that supersymmetry emerges naturally in a topological superconductor. An example is helium-3, a light, nonradioactive isotope of helium with two protons and one neutron (common helium has two neutrons). When helium-3 is cooled to almost absolute zero (0 Kelvin), it becomes a liquid superconductor. As understood only recently, the boundary of its container features fermions.
"The reason these fermions exist is related to time-reversal symmetry, which is unrelated to supersymmetry," said Grover. A video of an object tossed vertically up in the air is a good example of time-reversal symmetry. When the video is played back, it shows the object following the same parabolic trajectory through the air as it did when the video was played normally. "We wanted to see what would happen to these fermions when time-reversal symmetry was broken," Grover explained.
The scientists theorized that the application of a specified amount of magnetic field to the surface of the container would break the time-reversal symmetry. This, in turn, would cause the fermions to disappear due to their interaction with bosons that already exist in the liquid helium-3. Grover and his coauthors found that right at the point when fermions are about to disappear, the fermions and the bosons behave as superpartners of each other, thus providing a  analog of supersymmetry.
According to physicists, if supersymmetry can be proved in high-energy experiments, it opens the door to answers that physicists have been seeking for years and may pave the way to analyze and even integrate different fundamental physics theories such as quantum field theory, string theory and Einstein's relativity.
"Grover's team shows that supersymmetry may be studied in low-energy experiments," said physics professor Leon Balents, Grover's colleague at KITP. "This would be amazing in its own right and could serve as an inexpensive tabletop model for what to look for at particle accelerators."
"Our paper provides insight into how and in what systems supersymmetry may emerge in a very natural way," Grover said. "Maybe it doesn't exist in our actual universe, but there exist these condensed matter systems, such as topological superconductors, where supersymmetry can exist. This opens the window for experimentalists to go and test supersymmetry and its exciting consequences in real life."
More information: Emergent Space-Time Supersymmetry at the Boundary of a Topological Phase, www.sciencemag.org/content/early/2014/04/02/science.1248253.full

Comments

Post a Comment

Popular posts from this blog

Einstein’s Lost Theory Describes a Universe Without a Big Bang

Einstein with Edwin Hubble, in 1931, at the Mount Wilson Observatory in California, looking through the lens of the 100-inch telescope through which Hubble discovered the expansion of the universe in 1929.  Courtesy of the Archives, Calif Inst of Technology. In 1917, a year after Albert Einstein’s  general theory of relativity  was published—but still two years before he would become the international celebrity we know—Einstein chose to tackle the  entire universe . For anyone else, this might seem an exceedingly ambitious task—but this was Einstein. Einstein began by applying his  field equations of gravitation  to what he considered to be the entire universe. The field equations were the mathematical essence of his general theory of relativity, which extended Newton’s theory of gravity  to realms where speeds approach that of light and masses are very large. But his math was better than he wanted to believe—...
Post a Comment
Read more

There’s a Previously Undiscovered Organ in Your Body, And It Could Explain How Cancer Spreads

Ever heard of the interstitium? No? That’s OK, you’re not alone  —  scientists hadn’t either. Until recently. And, hey, guess what  —  you’ve got one! The interstitium is your newest organ. Scientists identified it for the first time because they are better able to observe living tissues at a microscopic scale, according to a recent study published  in  Scientific Reports , Scientists had long believed that connective tissue surrounding our organs was a thick, compact layer. That’s what they saw when they looked at it in the lab, outside the body, at least. But in a routine endoscopy (exploration of the gastrointestinal tract), a micro camera revealed something unexpected: When observed in a living body, the connective tissue turned out to be “an open, fluid-filled space supported by a lattice made of thick collagen bundles,” pathologist and study author Neil Theise  told  Research Gate . This network of channels is present throughout ...
Post a Comment
Read more

First light-bending calculator designed with metamaterials

Exotic materials that bend light in extreme ways could be used to perform complex mathematical operations, creating a new kind of analogue computer. Tools for manipulating light waves have taken off in recent years thanks to the development of  metamaterials . These materials have complex internal structures on scales smaller than the wavelength of the light they interact with, and so they produce unusual effects. Most famously, metamaterials promise to deliver " invisibility cloaks " that can route light around an object, making it seem to disappear. Nader Engheta  at the University of Pennsylvania, Philadelphia, and his colleagues decided to explore a different use for metamaterials, one that adapts the  old idea of analogue computing . Today's digital computers are based on electrical switches that are either on or off. But before these machines were analogue computers based on varying electrical or mechanical properties. The  slide rule  is one example...
Post a Comment
Read more