Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

"Spintronics" could enable a new generation of electronic devices

11.08.2003


Moore´s Law - a dictum of the electronics industry that says the number of transistors that fit on a computer chip will double every 18 months - may soon face some fundamental roadblocks. Most researchers think there´ll eventually be a limit to how many transistors they can cram on a chip. But even if Moore´s Law could continue to spawn ever-tinier chips, small electronic devices are plagued by a big problem: energy loss, or dissipation, as signals pass from one transistor to the next. Line up all the tiny wires that connect the transistors in a Pentium chip, and the total length would stretch almost a mile. A lot of useful energy is lost as heat as electrons travel that distance.

Theoretical physicists at Stanford and the University of Tokyo think they´ve found a way to solve the dissipation problem by manipulating a neglected property of the electron - its "spin", or orientation, typically described by its quantum state as "up" or "down."

They report their findings in the Aug. 7 issue of Science Express, an online version of Science magazine. Electronics relies on Ohms Law, which says application of a voltage to many materials results in the creation of a current. That´ because electrons transmit their charge through the materials. But Ohm´s Law also describes the inevitable conversion of electric energy into heat when electrons encounter resistance as they pass through materials.



"We have discovered the equivalent of a new `Ohm´s Law´ for spintronics - the emerging science of manipulating the spin of electrons for useful purposes," says Shoucheng Zhang, a physics professor at Stanford. Professor Naoto Nagaosa of the University of Tokyo and his research assistant, Shuichi Murakami, are Zhang´s co-authors. "Unlike the Ohm´s Law for electronics, the new `Ohm´s Law´ that we´ve discovered says that the spin of the electron can be transported without any loss of energy, or dissipation. Furthermore, this effect occurs at room temperature in materials already widely used in the semiconductor industry, such as gallium arsenide. That´s important because it could enable a new generation of computing devices."

Zhang uses a celestial analogy to explain two important properties of electrons - their center of mass and their spin: "The Earth has two kinds of motion. One is that its center of mass moves around the Sun. But the other is that it also spins by itself, or rotates. The way it moves around the Sun gives us the year, but the way it rotates around by itself gives us the day. The electron has similar properties." While electronics uses voltage to move an electron´s center of mass, spintronics uses voltage to manipulate its spin.

The authors predict that application of an electric field will cause electrons´ spins to flow together collectively in a current. The applied electric force, the spins and the spin current align in three different directions that are all perpendicular to each other.

"This is a remarkable thing," explains Zhang. "I push you forward and you move sideways - not in the direction that I´m pushing you."

So far, only superconductors are known to carry current without any dissipation. However, extremely low temperatures, typically -150 degree Celsius, are required for the dissipationless current to flow inside a superconductor. Unlike electronic superconductors being investigated in advanced laboratories throughout the world, whose operating temperatures are too low to be practical in commercial devices, Zhang, Nagaosa and Murakami theorize that the dissipationless spin current will flow even at room temperature.

"This [the work reported in the paper] is a theoretical prediction," Zhang says. "The next step is to work closely with experimental labs to verify this prediction and to demonstrate this effect." That will require creating materials and testing them with a sensitive spin detector. "Once this is done we can go ahead to propose different device structures which take advantage of this effect," he says.

Zhang characterizes his work as fundamental research but says spintronics is already making its way into devices in other labs. With lack of dissipation, spintronics may be the best mechanism for creating ever-smaller devices. The potential market is enormous, he says. "In maybe a 10-year timeframe, spintronics will be on par with electronics," he predicts. "That´s why there´s a huge race going on around the world."

The National Science Foundation and the Department of Energy in the United States and the Ministry of Education, Culture, Sports, Science and Technology in Japan funded the work.

Contact: Dawn Levy, +1-650-725-1944, dawnlevy@stanford.edu

Dawn Levy | EurekAlert!
Further information:
http://news-service.stanford.edu/news/2003/august20/zhang-video-820.html

More articles from Power and Electrical Engineering:

nachricht Linear potentiometer LRW2/3 - Maximum precision with many measuring points
17.05.2017 | WayCon Positionsmesstechnik GmbH

nachricht First flat lens for immersion microscope provides alternative to centuries-old technique
17.05.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>