New energy pattern observed at National High Magnetic Field Laboratory
2013 05 17

By Thomas Anderson | TGDaily

Two research teams at the National High Magnetic Field Laboratory (MagLab) smashed through a nearly 40-year barrier recently when they observed a never-before-seen energy pattern.

The butterfly-shaped pattern was first theorized by physicist Douglas Hofstadter in 1976, but it took the tools and technology now available at the MagLab to prove its existence.

"The observation of the ’Hofstadter butterfly’ marks a real landmark in condensed matter physics and high magnetic field research," said Greg Boebinger, director of the MagLab. "It opens a new experimental direction in materials research."

This groundbreaking research demanded the ability to measure samples of materials at very low temperatures and very high magnetic fields, up to 35 tesla. Both of those conditions are available at the MagLab, making it an international destination for scientific exploration.

The unique periodic structure used to observe the butterfly pattern was composed of boron nitride (BN) and graphene. Graphene is a Nobel Prize-winning material that holds tremendous promise in revolutionizing computers, batteries, cell phones, televisions and even airplanes. A one-atom thick, honeycomb array of carbon atoms, graphene is virtually see-through, yet 300 times stronger than steel and 1,000 times more conducting than silicon.

"This is about a puzzle that has been solved," said Eric Palm, deputy director at the MagLab. "It is really about scientific curiosity. It is an exciting confirmation of a theory that was made years ago."

MagLab physicist Nicholas Bonesteel agreed, adding "The Hofstadter butterfly is a beautiful fractal energy pattern that has intrigued physicists for decades. Seeing clear experimental evidence for it is a real breakthrough."

[...]

Read the full article at: tgdaily.com




What the teams did was place graphene – a layer of carbon just one atom thick – on an extremely flat surface of a boron-nitride crystal. As both materials have similar hexagonal structures, the researchers observed "Moiré patterns", which are regular patterns created whenever two similar 2D lattices are overlaid. (The Manchester and MIT groups used single-layer graphene, while the Columbia-led experiment involved bilayer graphene.) By tweaking the relative orientation of the two lattices, the teams were able to create superlattices with appropriate spacing. Source


Butterfly seen at long last





Related Articles
Nature: Hofstadter’s butterfly and the fractal quantum Hall effect in moiré superlattices
Scientists use magnetic nano-rods to investigate how matter assembles
New Discovery Provides Unprecedented Control of Magnetic Fields


Latest News from our Front Page

Hungary’s Orban Bashes Liberal Immigration Policy
2014 08 29
Hungary’s Prime Minister Viktor Orban on Monday lashed out against immigration, setting one of the main policy objectives of his next term in power after winning parliamentary elections in April. “The goal is to cease immigration whatsoever,” said Hungary’s prime minister. “I think the current liberal immigration policy, which is considered obvious and morally based, is hypocrite,” Mr. Orban said. At a ...
China’s “Duplitecture” Cities Mimic the World’s Greatest Architectural Hits
2014 08 29
The best knockoffs in the world are in China. There are plenty of fake designer handbags and Rolexes, but China’s knockoffs go way beyond fashion. There are knockoff Apple stores that look so much like the real thing that some employees believe they are working in real Apple stores. And then there are entire knockoff cities. There are Venices with ...
Kiev loses control of Novoazovsk, rebel troops advance in southeast Ukraine
2014 08 29
Kiev’s troops had to leave the eastern Ukrainian city of Novoazovsk to save their lives, said the country’s Security and Defense Council. The authorities admitted that self-defense forces are advancing and leading a counteroffensive in the southeast. Along with Novoazovsk, Kiev troops have lost control over the villages of Amvrosiivka and Starobeshevo in the Donetsk Region of Eastern Ukraine. According to Ukraine’s ...
Mohammed is most popular name in Oslo
2014 08 29
For the first time in the capital city’s history, Mohammed is the most common name for boys and men, said a study on Thursday. Statistics Norway (Statistisk Sentralbyrå - SSB) has counted the population of Oslo and found that Mohammed is the most common male name in Oslo for the first time ever. Jørgen Ouren of SSB said to NRK: “It is ...
Beaten to Death at McDonald’s
2014 08 29
To the four clean-cut college freshman out on a double date, it had seemed like a typical McDonald’s: spanking clean, well-lighted, and safe. It was in a good neighborhood too, right next to Texas A&M University in College Station -- a campus known for its friendly atmosphere and official down-home greeting: “howdy.” Shortly after 2 A.M. that Sunday, they pulled into ...
More News »