New wave of electron research

A diagram of the experimental setup pioneered by the team.
Credit: © 2021 Shin et al.

A surprise result for solid state physicists hints at an unusual electron behavior.

While studying the behavior of electrons in iron-based superconducting materials, researchers at the University of Tokyo observed a strange signal relating to the way electrons are arranged. The signal implies a new arrangement of electrons the researchers call a nematicity wave, and they hope to collaborate with theoretical physicists to better understand it. The nematicity wave could help researchers understand the way electrons interact with each other in superconductors.

A long-standing dream of solid state physicists is to fully understand the phenomenon of superconductivity — essentially electronic conduction without the resistance that creates heat and drains power. It would usher in a whole new world of incredibly efficient or powerful devices and is already being used on Japan’s experimental magnetic levitation bullet train. But there is much to explore in this complex topic, and it often surprises researchers with unexpected results and observations.

Professor Shik Shin from the Institute for Solid State Physics at the University of Tokyo and his team study the way electrons behave in iron-based superconducting materials, or IBSCs. These materials show a lot of promise as they could work at higher temperatures than some other superconducting materials which is an important concern. They also use less exotic material components so can be easier and cheaper to work with. To activate a sample’s superconducting ability, the material needs to be cooled down to several hundreds of degrees below zero. And interesting things happen during this cooling process.

“As IBSCs cool down to a certain level, they express a state we call electronic nematicity,” said Shin. “This is where the crystal lattice of the material and the electrons within it appear to be arranged differently depending on the angle you look at them, otherwise known as anisotropy. We expect the way electrons are arranged to be tightly coupled to the way the surrounding crystal lattice is arranged. But our recent observation shows something very different and actually quite surprising.”

Shin and his team used a special technique developed by their group called laser-PEEM (photoemission electron microscopy) to visualize their IBSC sample on the microscopic scale. They expected to see a familiar pattern that repeats every few nanometers (billionths of a meter). And sure enough the crystal lattice did show this pattern. But to their surprise, the team found that the pattern of electrons was repeating every few hundred nanometers instead.

This disparity between the electron nematicity wave and the crystalline structure of the IBSC was unexpected, so its implications are still under investigation. But the result could open the door to theoretical and experimental explorations into something fundamental to the phenomenon of superconductivity, and that is the way that electrons form pairs at low temperatures. Knowledge of this process could be crucial to the development of high-temperature superconductivity. So if nematicity waves are related, it is important to know how.

“Next, I hope we can work with theoretical physicists to further our understanding of nematicity waves,” said Shin. “We also wish to use laser-PEEM to study other related materials such as metal oxides like copper oxide. It may not always be obvious where the applications lie, but working on problems of fundamental physics really fascinates me.”

###

Journal article

T. Shimojima, Y. Motoyui, T. Taniuchi, C. Bareille, S. Onari, H. Kontani, M. Nakajima, S. Kasahara, T. Shibauchi, Y. Matsuda, S. Shin, “Discovery of mesoscopic nematicity wave in iron-based superconductors”, Science, DOI: 10.1126/science.abd6701

Link: https://doi.org/10.1126/science.abd6701

 

Funding
This work was supported by Grants-in-Aid for Scientific Research (Nos. JP18H05227, JP19H00649, JP19H00651) and on Innovative Areas “Quantum Liquid Crystals” (Nos. JP19H05823, JP19H05824) from Japan Society for the Promotion of Science.

 

Useful links
The Institute for Solid State Physics – http://www.issp.u-tokyo.ac.jp/index_en.html
Shin Laboratory – https://shin.issp.u-tokyo.ac.jp/

Research contact information
Professor Shik Shin
The Institute for Solid State Physics, The University of Tokyo,
Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581, JAPAN
Email: shin@issp.u-tokyo.ac.jp

Press Contact

Mr. Rohan Mehra

Division for Strategic Public Relations, The University of Tokyo

7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, JAPAN

Email: press-releases.adm@gs.mail.u-tokyo.ac.jp

 

About the University of Tokyo

The University of Tokyo is Japan’s leading university and one of the world’s top research universities. The vast research output of some 6,000 researchers is published in the world’s top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 4,000 international students. Find out more at www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

Journal: Science
DOI: 10.1126/science.abd6701
Method of Research: Experimental study
Subject of Research: Not applicable
Article Title: Discovery of mesoscopic nematicity wave in iron-based superconductors
Article Publication Date: 1-Sep-2021

Media Contact

Rohan Mehra

press-releases.adm@gs.mail.u-tokyo.ac.jp
Office: 81-358-411-045

Expert Contact

Professor Shik Shin

shin@issp.u-tokyo.ac.jp

Original Source

https://www.u-tokyo.ac.jp/focus

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors