Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Measuring the Smallest Magnets

Abstract:
Imagine trying to measure a tennis ball that bounces wildly, every time to a distance a million times its own size. The bouncing obviously creates enormous "background noise" that interferes with the measurement. But if you attach the ball directly to a measuring device, so they bounce together, you can eliminate the noise problem.

Measuring the Smallest Magnets

Rehovot, Israel | Posted on July 28th, 2014

As reported recently in Nature, physicists at the Weizmann Institute of Science used a similar trick to measure the interaction between the smallest possible magnets - two single electrons - after neutralizing magnetic noise that was a million times stronger than the signal they needed to detect.



Dr. Roee Ozeri of the Institute's Physics of Complex Systems Department says: "The electron has spin, a form of orientation involving two opposing magnetic poles. In fact, it's a tiny bar magnet." The question is whether pairs of electrons act like regular bar magnets in which the opposite poles attract one another.



Dr. Shlomi Kotler performed the study while a graduate student under Dr. Ozeri's guidance, with Drs. Nitzan Akerman, Nir Navon and Yinnon Glickman. Detecting the magnetic interaction of two electrons poses an enormous challenge: When the electrons are at a close range - as they normally are in an atomic orbit - forces other than the magnetic one prevail. On the other hand, if the electrons are pulled apart, the magnetic force becomes dominant, but so weak in absolute terms that it's easily drowned out by ambient magnetic noise emanating from power lines, lab equipment and the earth's magnetic field.



The scientists overcame the problem by borrowing a trick from quantum computing that protects quantum information from outside interference. This technique binds two electrons together so that their spins point in opposite directions. Thus, like the bouncing tennis ball attached to the measuring device, the combination of equal but opposite spins makes the electron pair impervious to magnetic noise.



The Weizmann scientists built an electric trap in which two electrons are bound to two strontium ions that are cooled close to absolute zero and separated by 2 micrometers (millionths of a meter). At this distance, which is astronomic by the standards of the quantum world, the magnetic interaction is very weak. But because the electron pairs were not affected by external magnetic noise, the interactions between them could be measured with great precision. The measurement lasted for 15 seconds - tens of thousands of times longer than the milliseconds during which scientists have until now been able to preserve quantum data.



The measurements showed that the electrons interacted magnetically just as two large magnets do: Their north poles repelled one another, rotating on their axes until their unlike poles drew near. This is in line with the predictions of the Standard Model, the currently accepted theory of matter. Also as predicted, the magnetic interaction weakened as a function of the distance between them to the power of three.



In addition to revealing a fundamental principle of particle physics, the measurement approach may prove useful in such areas as the development of atomic clocks or the study of quantum systems in a noisy environment.



Dr. Roee Ozeri's research is supported by the Crown Photonics Center; the Yeda-Sela Center for Basic Research; the Wolfson Family Charitable Trust; Martin Kushner Schnur, Mexico; Friends of the Weizmann Institute of Science in Memory of Richard Kronstein; and the Zumbi Stiftung.

####

About The Weizmann Institute of Science
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.

For more information, please click here

Contacts:
Batya Greenman

Department of Media Relations

Weizmann Institute of Science

PO Box 26

Rehovot, 7610001, ISRAEL

Tel: 972-8-934-3852

Fax: 972-8-934-4132

Copyright © The Weizmann Institute of Science

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

Link to scientific article:

Related News Press

News and information

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials July 27th, 2016

Physics

Ultra-flat circuits will have unique properties: Rice University lab studies 2-D hybrids to see how they differ from common electronics July 25th, 2016

Attosecond physics: Mapping electromagnetic waveforms July 25th, 2016

Entanglement: Chaos - Researchers at UCSB blur the line between classical and quantum physics by connecting chaos and entanglement July 14th, 2016

Physicists couple distant nuclear spins using a single electron: For the first time, researchers at the University of Basel have coupled the nuclear spins of distant atoms using just a single electron July 12th, 2016

Discoveries

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials July 27th, 2016

Scientists test nanoparticle drug delivery in dogs with osteosarcoma July 26th, 2016

Announcements

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials July 27th, 2016

Quantum nanoscience

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

A new spin on reality July 15th, 2016

Physicists couple distant nuclear spins using a single electron: For the first time, researchers at the University of Basel have coupled the nuclear spins of distant atoms using just a single electron July 12th, 2016

Quantum technologies to revolutionize 21st century: Nobel Laureates to discuss impacts at 66th Lindau Meeting July 5th, 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