Plasmas have been recently studied as topological materials. However, a comprehensive picture of topological phases and topological phase transitions in cold magnetized plasmas are still missing.
Scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have discovered 10 unique phases of magnetized plasma and their transitions. These transitions then prompt localized wave excitations that could have applications in space and laboratory plasmas.
These newly discovered phases are technically known as topological phases, indicating the shapes of the waves supported by plasma.
The discovery was made via a newly discovered way of classifying magnetized plasmas.
Physicist Hong Qin, a co-author of the paper and Fu’s advisor, said, “The discovery of the 10 phases in plasma marks a primary development in plasma physics. The first and foremost step in any scientific endeavor is to classify the objects under investigation. Any new classification scheme will lead to improvement in our theoretical understanding and subsequent advances in technology.”
Scientists could use the excitations to create a current in magnetic fusion plasmas or facilitating plasma rotation in fusion experiments.
Fusion, which combines light elements in plasma, releases a massive amount of energy, a safe and clean source of power for generating electricity.
Qin said, “The localized plasma waves produced by phase transitions are robust and intrinsic because they are ‘topologically protected. The discovery that this topologically protected excitation exists in magnetized plasmas is a big step forward that can be explored for practical applications.”
Yichen Fu, a graduate student at PPPL, said, “The most important progress in the paper is looking at plasma based on its topological properties and identifying its topological phases. Based on these phases, we identify the necessary and sufficient conditions for the excitations of these localized waves. As for how this progress can be applied to facilitate fusion energy research, we have to find out.”
- Yichen Fu et al., Topological phases and bulk-edge correspondence of magnetized cold plasmas, Nature Communications (2021). DOI: 10.1038/s41467-021-24189-3