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 Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>