One kind of supersymmetry shown to emerge naturally

Apr 09, 2014 by Julie Cohen
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."

Explore further: Electron's shapeliness throws a curve at supersymmetry

More information: Emergent Space-Time Supersymmetry at the Boundary of a Topological Phase, www.sciencemag.org/content/ear… science.1248253.full

add to favorites email to friend print save as pdf

Related Stories

ATLAS sees Higgs boson decay to fermions

Nov 28, 2013

The ATLAS experiment at CERN has released preliminary results that show evidence that the Higgs boson decays to two tau particles. Taus belong to a group of subatomic particles called the fermions, which ...

What's next for particle physicists, post-Higgs?

Jul 17, 2013

In March of last year, scientists working with the Large Hadron Collider at the European Organization for Nuclear Research in Geneva, Switzerland, identified the Higgs boson, the last elusive particle in the Standard Model ...

12 matter particles suffice in nature

Dec 13, 2012

How many matter particles exist in nature? Particle physicists have been dealing with this question for a long time. The 12 matter particles contained in the standard model of particle physics? Or are there ...

Electron's shapeliness throws a curve at supersymmetry

Dec 19, 2013

A small band of particle-seeking scientists at Yale and Harvard has established a new benchmark for the electron's almost perfect roundness, raising doubts about certain theories that predict what lies beyond ...

The Higgs boson: One year on

Jul 05, 2013

A year ago today, physicists from the ATLAS and CMS experiments at CERN proudly announced the discovery of a new boson looking very much like the Higgs boson.

Recommended for you

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

rah
1 / 5 (2) Apr 09, 2014
No, none of that happened. This is all complete nonsense. these guys are living in fear of losing their funding, as they should be, so they produce this tripe. I'll show you about 4.45 inches of supersymmetry right here.
Noumenon
5 / 5 (2) Apr 10, 2014
No, none of that happened. This is all complete nonsense. these guys are living in fear of losing their funding, as they should be, so they produce this tripe. I'll show you about 4.45 inches of supersymmetry right here.


So, they would have two reasons to laugh at you then.
aau93940
not rated yet Apr 10, 2014
The scientists theorized ...that supersymmetry may be studied
In another words, they didn't show anything. It's just another theoretical study about theoretical phenomena, which has been already disproved experimentally. The abstract clearly says
..we theoretically show that SUSY emerges in condensed matter systems known as topological superconductor...
aau93940
not rated yet Apr 10, 2014
The above article implies, that the SUSY requires time-reversal symmetry breaking to work. If the dark matter is attributed to WIMP particles predicted with SUSY, it would mean, that the T-symmetry breaking is widespread phenomena, because the dark matter accounts for 83 percent of the matter in the Universe. But in fact the T-symmetry breaking was never observed experimentally even at the way more sensitive experiments and its breaking would broke even the theories, on which supersymmetry is based. Such an insight would render the SUSY as an intrinsically inconsistent theory.
vlaaing peerd
not rated yet Apr 11, 2014
Super symmetry has not been found, that doesn't mean it has been completely disproved. And as far as I understand the article correctly, they have proposed a way of testing and studying it.

Perhaps it's just my unscientific POV, but as longs as SUSY (and theories like string) still have the potential to be an extension to our current theories they remain well worth investigating. Even if they turn out to be wrong, it's still good to know for sure they are.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.