Nav: Home

Topological waves may help in understanding plasma systems

May 14, 2020

PROVIDENCE, R.I. [Brown University] -- Nearly 50 years ago, Brown University physicist Michael Kosterlitz and his colleagues used the mathematics of topology -- the study of how objects can be deformed by stretching or twisting but not tearing or breaking -- to explain puzzling phase changes in certain types of matter. The work won Kosterlitz a share of the 2016 Nobel Prize in Physics and has led to the discovery of topological phenomena in all kinds of systems, from thin films that conduct electricity only around their edges, to strange waves that propagate in the oceans and atmosphere at the Earth's equator.

Now a team of researchers, including another Brown physicist, has added a new topological phenomenon to that ever-growing list. In new theoretical research, the team shows that electromagnetic waves of topological origin should be present on the surface of plasmas -- hot soups of ionized gas. If the theory proves true, those waves could provide a new way for scientists to probe the properties of plasmas, which are found in everything from fluorescent lightbulbs to stars.

The research was led by Jeffrey Parker, a research scientist at Lawrence Livermore National Laboratory, in collaboration with Brad Marston, a professor of physics at Brown, and others. The paper is published in Physical Review Letters.

The waves, called gaseous plasmon polaritons, propagate along the interface of a plasma and its surroundings when the system is exposed to a strong magnetic field. Marston says that what's interesting about these waves is that they are "topologically protected," meaning that they're inherently present in the system and are resistant to being scattered by impurities.

"Any time you have a wave that's protected against scattering, it means they can stay intact over a long distance," Marston said. "As a practical matter, we're hoping that these can be used to diagnose plasma states. One of the big problems in plasma physics is to figure out the state of a plasma without disturbing it. If you stick in a probe, you're going to disrupt the system. We might be able to use these waves to discern the state of a plasma without disturbing it."

One way to think about topological protection, Marston says, is something known as the hairy ball theorem. Imagine a ball covered in long hairs. If one were to try to comb those hairs down, there will always be at least one spot on the ball where the hairs won't lie flat.

"This spot will always be there," Marston said. "You can move it around, but the only way to get rid of it is to tear some hair out. But barring something violent like that, if you're just manipulating it continuously without tearing anything, there's always going to be a vortex."

The ever-present vortex on the hairy ball is mathematically analogous to the waves on a plasma's surface, Marston says.

"In this case, there's always a vortex but it's in the wave-number space, wavelengths of the different waves," he said. "It's a little more abstract than in real space, but the math is largely similar."

Having fleshed out the theoretical basis for these waves, the next step is to perform experiments to confirm that they're really there. Marston and his colleagues recently won a seed grant from Brown to help them do just that. With the help of researchers at UCLA's Basic Plasma Physics Facility, Marston and his colleagues plan to perform experiments to detect these waves.

Ultimately, Marston hopes that the discovery of these waves could be a boon for plasma physics, helping scientists to better understand and control plasma systems. One major area Marston is interested in is plasma fusion reactors. Such reactors could one day harness nuclear fusion to produce an abundance of clean energy, but so far the plasma systems have proven hard to control.

"In the long term, we hope this can make an impact on fusion energy," Marston said. "If we can use these waves to discern the states of plasmas, it might help in designing a fusion reactor that's stable and able to produce energy."

But for now, Marston and his colleagues are looking forward to performing their experiments.

"If we can demonstrate these things experimentally, people in the plasma community will hopefully start paying closer attention to this idea," he said.

Other co-authors on the paper were Steven Tobias and Ziyan Zhu.
-end-


Brown University

Related Plasma Articles:

Topological waves may help in understanding plasma systems
A research team has predicted the presence of 'topologically protected' electromagnetic waves that propagate on the surface of plasmas, which may help in designing new plasma systems like fusion reactors.
Plasma electrons can be used to produce metallic films
Computers, mobile phones and all other electronic devices contain thousands of transistors, linked together by thin films of metal.
Plasma-driven biocatalysis
Compared with traditional chemical methods, enzyme catalysis has numerous advantages.
How bacteria protect themselves from plasma treatment
Considering the ever-growing percentage of bacteria that are resistant to antibiotics, interest in medical use of plasma is increasing.
A breakthrough in the study of laser/plasma interactions
Researchers from Lawrence Berkeley National Laboratory and CEA Saclay have developed a particle-in-cell simulation tool that is enabling cutting-edge simulations of laser/plasma coupling mechanisms.
Researchers turn liquid metal into a plasma
For the first time, researchers at the University of Rochester's Laboratory for Laser Energetics (LLE) have found a way to turn a liquid metal into a plasma and to observe the temperature where a liquid under high-density conditions crosses over to a plasma state.
How black holes power plasma jets
Cosmic robbery powers the jets streaming from a black hole, new simulations reveal.
Give it the plasma treatment: strong adhesion without adhesives
A Japanese research team at Osaka University used plasma treatment to make fluoropolymers and silicone resin adhere without any adhesives.
Chemotherapeutic drugs and plasma proteins: Exploring new dimensions
This review provides a bird's eye view of interaction of a number of clinically important drugs currently in use that show covalent or non-covalent interaction with serum proteins.
The coming of age of plasma physics
The story of the generation of physicists involved in the development of a sustainable energy source, controlled fusion, using a method called magnetic confinement.
More Plasma News and Plasma Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Processing The Pandemic
Between the pandemic and America's reckoning with racism and police brutality, many of us are anxious, angry, and depressed. This hour, TED Fellow and writer Laurel Braitman helps us process it all.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Invisible Allies
As scientists have been scrambling to find new and better ways to treat covid-19, they've come across some unexpected allies. Invisible and primordial, these protectors have been with us all along. And they just might help us to better weather this viral storm. To kick things off, we travel through time from a homeless shelter to a military hospital, pondering the pandemic-fighting power of the sun. And then, we dive deep into the periodic table to look at how a simple element might actually be a microbe's biggest foe. This episode was reported by Simon Adler and Molly Webster, and produced by Annie McEwen and Pat Walters. Support Radiolab today at Radiolab.org/donate.