Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Detecting tiny twists with a nanomachine

04.11.2008
Nanoscale device may reveal spin-dependent fundamental forces and provide new methods of characterizing torque-generating molecules and DNA strands

Researchers at Boston University working with collaborators in Germany, France and Korea have developed a nanoscale torsion resonator that measures miniscule amounts of twisting or torque in a metallic nanowire.

This device, the size of a speck of dust, might enable measurements of the untwisting of DNA and have applications in spintronics, fundamental physics, chemistry and biology.

Spin-induced torque is central to understanding experiments, from the measurement of angular momentum of photons to the measurement of the gyromagnetic factor of metals and a very miniaturized – about 6 microns -- version of a gyroscope that measures the torques produced by electrons changing their spin states. It can be used to uncover new spin-dependent fundamental forces in particle physics, according to Raj Mohanty, Boston University Associate Professor of Physics.

"This is perhaps the most sensitive torque measurement every reported," said Mohanty. "The size of the torque measured by this experiment is smaller than the typical torque produced by the untwisting of a doubly-stranded DNA."

In a just released paper in Nature Nanotechnology entitled "Nanomechanical detection of itinerant electron spin flip," Mohanty and his research team developed a highly sensitive way to directly measure torque using microelectronic mechanical systems with spin electronics. Their approach was to detect and control spin-flip torque -- a phenomenon that occurs in a metallic nanowire, that is half ferromagnetic and the other is nonmagnetic. The spins of itinerant electrons are "flipped" at the interface between the two regions to produce a torque.

The team developed a microscopic spin-torsion device fabricated by electron beam lithography and nanomachining that mechanically measures the changes in spin states in a magnetic field. This device was operated at one tenth of a degree close to absolute zero.

The team has been working on demonstrating the opposite effect. Under the application of an external torque spin-up and spin-down electrons can be separated to two physically distinct locations, creating a spin battery. This is similar to a conventional charge battery with positive and negative polarities. When connected with an electrical path, electricity flows from one side to the other. But instead of electric current, the flow in the spin battery involves the spin – which can be used to store and manipulate information, the basis of an emerging technology called spintronics.

"The measurements with a nanoscale torsion resonator will be useful in uncovering new fundamental forces and, in theory, for characterizing torque producing molecules and DNA." said Mohanty.

Ronald Rosenberg | EurekAlert!
Further information:
http://www.bu.edu

More articles from Physics and Astronomy:

nachricht Gamma rays will reach beyond the limits of light
23.10.2017 | Chalmers University of Technology

nachricht Creation of coherent states in molecules by incoherent electrons
23.10.2017 | Tata Institute of Fundamental Research

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>