Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Ben-Gurion University scientist solves nanoelectronics puzzle

Abstract:
Ben-Gurion University of the Negev's theoretical physicist, Professor Yigal Meir has solved one of nanoelectronic's most longstanding puzzles, which has baffled physicists seeking to make smaller, faster computer devices for more than a decade.

Ben-Gurion University scientist solves longstanding nanoelectronics puzzles

Beer-Sheva, Israel | Posted on October 05, 2006

Ben-Gurion University of the Negev's theoretical physicist, Professor Yigal Meir has solved one of nanoelectronic's most longstanding puzzles, which has baffled physicists seeking to make smaller, faster computer devices for more than a decade.

Nanoelectronics refers to electronic transport through miniaturized devices. The simplest such device, and the basic building block for more complicated devices, is a quantum point contact, a constriction connecting large electron reservoirs.

In a paper published in Nature Magazine, the professor explains the 0.7 anomaly, a feature in the conductance of quantum point contacts that has so far eluded explanation for almost 20 years.

According to quantum mechanics, and the wavelike nature of electrons, scientists expected the conductance through such a device to increase as the gap grew bigger by integer steps of universal value. While this was indeed found true in early experiments, surprisingly, an additional first step, approximately 0.7 times the expected universal value had also been observed, which scientists first attributed to irregularities in the device (the 0.7 anomaly as it became known).

While visiting Princeton University, Meir and a colleague, Ned Wingreen, theorized the existence of a magnetic impurity, a localized electron, in a quantum-point contact to explain the 0.7 anomaly. While their theoretical calculations explained its temperature and magnetic-field dependence, they still needed to identify the proposed impurity to overcome physics community skeptics about how a magnetic moment could form in such a system. The classical analogy of a quantum point contact is a sea of electrons around a hill, Meir explains. The existence of a magnetic impurity on the point of contact is equivalent to the formation of a puddle of water at the top of the hill, a counterintuitive phenomenon.

In the Nature paper published with his Ben-Gurion University postdoc, Dr. Tomaz Rejec, Meir explains, via extensive numerical calculations, that the existence of a magnetic impurity at the quantum point of contact is possible because a lower density of the electrons near the quantum point attracts the other electrons toward the point. The wavy nature of such electrons then causes the quantum point to form ripples, trapping an electron and causing the 0.7 anomaly.

This is both good and bad news for quantum computer devices based on quantum dots which require that no outside factors affect the circuits, Meir concludes. Magnetic impurities at point contacts would render such computer devices inoperable. However, the magnetic impurity is formed only when conductance through the point of contact is around 0.7, so setting the conductance of each contact below that value should allow a circuit formed by quantum dots to function.

####

About Ben-Gurion University of the Negev:
Ben-Gurion University of the Negev is more than a world-renowned institute of research and higher learning. BGU builds bridges of peace between Israel and it neighbors through cooperation in science, research and development. It is the link between academia and industry, Israel and the developing world. BGU is a university with a conscience, where the highest academic and scientific standards are integrated with community involvement, and where the dream of Israelís first Prime Minister, David Ben-Gurion, to make the desert bloom is fulfilled.

For more information, please click here

About American Associates, Ben-Gurion University of the Negev:
Founded in 1972, AABGU is a partner in the University's mission to develop the Negev and build a world-class institution of research and education in the desert. A nonprofit organization with its national headquarters in New York City and 10 regional offices throughout the United States, AABGU plays a vital role in helping BGU fulfill its unique responsibility to develop the bold new vision for the Negev, the focus of the future of Israel and the world.

For more information, please click here

Contact:
Andrew Lavin
andrewlavin@alavin.com

Copyright © Ben-Gurion University of the Negev

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 News Press

Quantum Computing

Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024

Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024

With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024

Chemical reactions can scramble quantum information as well as black holes April 5th, 2024

Nanoelectronics

Interdisciplinary: Rice team tackles the future of semiconductors Multiferroics could be the key to ultralow-energy computing October 6th, 2023

Key element for a scalable quantum computer: Physicists from Forschungszentrum Jülich and RWTH Aachen University demonstrate electron transport on a quantum chip September 23rd, 2022

Reduced power consumption in semiconductor devices September 23rd, 2022

Atomic level deposition to extend Moore’s law and beyond July 15th, 2022

Discoveries

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Advances in priming B cell immunity against HIV pave the way to future HIV vaccines, shows quartet of new studies May 17th, 2024

Announcements

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project