Featured Research

from universities, journals, and other organizations

Catching graphene butterflies: Dramatically changing electronic properties of world's thinnest material

Date:
May 15, 2013
Source:
University of Manchester
Summary:
A large international team of researchers has shown that when graphene placed on top of insulating boron nitride, or 'white graphene', the electronic properties of graphene change dramatically revealing a pattern resembling a butterfly. The pattern is referred to as the elusive Hofstadter butterfly that has been known in theory for many decades but never before observed in experiments.

Graphene, combined with white graphene, forms stunning 'butterfly' images.
Credit: The University of Manchester

Writing in Nature, a large international team led Dr Roman Gorbachev from The University of Manchester shows that, when graphene placed on top of insulating boron nitride, or 'white graphene', the electronic properties of graphene change dramatically revealing a pattern resembling a butterfly.

Related Articles


The pattern is referred to as the elusive Hofstadter butterfly that has been known in theory for many decades but never before observed in experiments.

Combining graphene with other materials in multiple-layered structures could lead to novel applications not yet explored by science or industry.

Graphene is the world's thinnest, strongest and most conductive material, and promises a vast range of diverse applications; from smartphones and ultrafast broadband to drug delivery and computer chips. It was first demonstrated at The University of Manchester in 2004.

Initial trials of consumer products involving graphene-based touch screens and batteries for mobile phones and composite materials for sports goods are being carried out by major multinational companies.

One of the most remarkable properties of graphene is its high conductivity -- thousands of times higher than copper. This is due to a very special pattern created by electrons that carry electricity in graphene. The carriers are called Dirac fermions and mimic massless relativistic particles called neutrinos, studies of which usually require huge facilities such as at CERN. The possibility to address similar physics in a desk-top experiment is one of the most renowned features of graphene.

Now the Manchester scientists have found a way to create multiple clones of Dirac fermions. Graphene is placed on top of boron nitride so that graphene's electrons can 'feel' individual boron and nitrogen atoms. Moving along this atomic 'washboard', electrons rearrange themselves once again producing multiple copies of the original Dirac fermions.

The researchers can create even more clones by applying a magnetic field. The clones produce an intricate pattern; the Hofstadter butterfly. It was first predicted by mathematician Douglas Hofstadter in 1976 and, despite many dedicated experimental efforts, no more than a blurred glimpse was reported before.

In addition to the described fundamental interest, the Manchester study proves that it is possible to modify properties of atomically-thin materials by placing them on top of each other. This can be useful, for example, for graphene applications such as ultra-fast photodetectors and transistors, providing a way to tweak its incredible properties.

Professor Andre Geim, Nobel Laureate and co-author of the paper, said: "Of course, it is nice to catch the beautiful 'butterfly' which elusiveness tormented physicists for generations.

"More importantly, this work shows that we are now able to build up a principally new kind of materials by stacking individual atomic planes in a desired sequence."

Dr Gorbachev added: "We prepared a set of different atomically-thin materials similar to graphene then stacked them on top of each other, one atomic plane at a time. Such artificial crystals would have been science fiction a few years ago. Now they are reality in our lab. One day you might find these structures in your gadgets."

Professor Geim added: "This is an important step beyond 'simple graphene'. We now build foundations for a new research area that seems richer and even more important than graphene itself."

The Manchester paper is collaboration that involved researchers from the University of Lancaster in the UK, Instituto de Ciencia de Materiales de Madrid in Spain and National High-Field Laboratory in Grenoble, France.

It will appear in Nature back to back with another paper reporting similar butterflies in two layers of graphene, which comes from a group of Dr Philip Kim, Columbia University.


Story Source:

The above story is based on materials provided by University of Manchester. Note: Materials may be edited for content and length.


Journal Reference:

  1. L. A. Ponomarenko, R. V. Gorbachev, G. L. Yu, D. C. Elias, R. Jalil, A. A. Patel, A. Mishchenko, A. S. Mayorov, C. R. Woods, J. R. Wallbank, M. Mucha-Kruczynski, B. A. Piot, M. Potemski, I. V. Grigorieva, K. S. Novoselov, F. Guinea, V. I. Fal’ko, A. K. Geim. Cloning of Dirac fermions in graphene superlattices. Nature, 2013; DOI: 10.1038/nature12187

Cite This Page:

University of Manchester. "Catching graphene butterflies: Dramatically changing electronic properties of world's thinnest material." ScienceDaily. ScienceDaily, 15 May 2013. <www.sciencedaily.com/releases/2013/05/130515131547.htm>.
University of Manchester. (2013, May 15). Catching graphene butterflies: Dramatically changing electronic properties of world's thinnest material. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2013/05/130515131547.htm
University of Manchester. "Catching graphene butterflies: Dramatically changing electronic properties of world's thinnest material." ScienceDaily. www.sciencedaily.com/releases/2013/05/130515131547.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins