Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Scientists capture first direct proof of Hofstadter butterfly effect

UCF team Masa Ishigami and Jyoti Katoch work to capture the illusive Hofstadter's butterfly effect.

Credit: UCF
UCF team Masa Ishigami and Jyoti Katoch work to capture the illusive Hofstadter's butterfly effect.

Credit: UCF

Abstract:
A team of researchers from several universities - including UCF -has observed a rare quantum physics effect that produces a repeating butterfly-shaped energy spectrum in a magnetic field, confirming the longstanding prediction of the quantum fractal energy structure called Hofstadter's butterfly.

Scientists capture first direct proof of Hofstadter butterfly effect

Orlando, FL | Posted on May 17th, 2013

This discovery by the team paves the way for engineering new types of extraordinary nanoscale materials that can be used to develop smaller, lighter and faster electronics, including sensors, cell phones, tablets and laptops.

First predicted by American physicist Douglas Hofstadter in 1976, the butterfly pattern emerges when electrons are confined to a two-dimensional plane and subjected to both a periodic potential energy and a strong magnetic field. The Hofstadter butterfly is a fractal pattern—meaning that it contains shapes that repeat on smaller and smaller size scales. Fractals are common in systems such as fluid mechanics, but rare in the quantum mechanical world. The Hofstadter butterfly is one of the first quantum fractals theoretically discovered in physics but, until now, there has been no direct experimental proof of this spectrum.

Columbia University led the study and also involved scientists from the City University of New York, Tohoku University and the National Institute for Materials Science in Japan. Columbia prepared the sample and the UCF team measured the regular recurrence of the high-fidelity periodic pattern, engineered by inducing nanoscale ripples on graphene, a carbon material. The measured recurrence served as the essential proof that the measured spectrum was indeed the Hofstadter butterfly. The image that captured the evidence was taken in UCF Assistant Professor Masa Ishigami's laboratory.

The study is published in today's advance online publication of Nature www.nature.com/nature/journal/vaop/ncurrent/full/nature12186.html

Jyoti Katoch, Ishigami's graduate student, used a non-contact atomic force high-resolution microscope to image the ripples, which have the height of only 0.2 angstroms (twenty trillionth of a meter), to confirm that the observed Hofstadter butterfly spectrum indeed matched the theoretical prediction.

"The arrangement of individual atoms, even just one atom can drastically alter properties of nanoscale materials. That is the basis for nanotechnology," Ishigami said. "Atomic structures must be resolved to understand the properties of nanoscale materials. What we do here at UCF is to explain why nanoscale materials behave so different by resolving their atomic structures. Only when we understand the origin of the extraordinary properties of nanoscale materials, we can propel nanoscience and technology forward. What Jyoti has done here is to image how graphene is rippled to explain the observed Hofstadter spectrum."

UCF's laboratory utilizes a novel, the state-of-the-art microscopy technique to simultaneously determine the atomic structure and electronic properties of nanoscale materials such as graphene.

Katoch has been working with Ishigami since 2008, when Ishigami joined UCF. Katoch helped build the laboratory and developed the atomic-resolution capability critical to capturing the picture proof for this study.

Ishigami has a Ph.D. in physics from the University of California at Berkeley and a bachelor's degree in physics from the Massachusetts Institute of Technology. He has won multiple awards, including the Intelligence Community postdoctoral fellowship and the Hertz graduate fellowship, and has published more than 30 papers in journals including Science.

The College of Sciences, the Nanoscience technology center, and the office of research and commercialization (through a Presidential Initiative to fund major research equipment) supported the purchase and development of the atomic resolution microscope in the Ishigami lab. This research effort was supported by the National Science Foundation under its Faculty Early Career Development Program. (Grant No. 0955625).

####

About University of Central Florida
50 Years of Achievement: The University of Central Florida, the nation's second-largest university with nearly 60,000 students, is celebrating its 50th anniversary in 2013. UCF has grown in size, quality, diversity and reputation, and today the university offers more than 200 degree programs at its main campus in Orlando and more than a dozen other locations. Known as America's leading partnership university, UCF is an economic engine attracting and supporting industries vital to the region's success now and into the future.

For more information, please click here

Contacts:
Zenaida Gonzalez Kotala

407-823-6120

Copyright © University of Central Florida

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Download article:

Related News Press

News and information

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Physics

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

The quantum fridge: It all comes down to quantum physics: scientists at TU Wien have analyzed why some gases can be cooled down to extremely low temperatures February 2nd, 2016

Unconventional superconductivity near absolute zero temperature: Quantum critical point could be the reason for high temperature superconductivity February 2nd, 2016

Electrons and liquid helium advance understanding of zero-resistance: Study of electrons on liquid helium systems sheds light on zero-resistance phenomenon in semiconductors February 2nd, 2016

Imaging

Cornell researchers create first self-assembled superconductor February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

LC.300 Series Nanopositioning Controller from nPoint January 28th, 2016

Researchers from the California NanoSystems Institute at UCLA have created a new technique that greatly enhances digital microscopy images January 27th, 2016

Discoveries

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Joint Efforts by Iranian, Malaysian Scientists Produce Antibacterial Coatings for Isolated Areas February 4th, 2016

Announcements

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Tools

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Cornell researchers create first self-assembled superconductor February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

LC.300 Series Nanopositioning Controller from nPoint January 28th, 2016

Quantum nanoscience

Spin dynamics in an atomically thin semi-conductor February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

Leti to Host Workshop on New Photonics Applications During SPIE Photonics West: Researchers also Will Present Four Invited Papers At Feb. 13-18 Conference, 14 Papers, Overall January 25th, 2016

Mechanical quanta see the light January 20th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic