Technical

The DEPSCoR grant will enable Appelbaum and his team to explore the use of spin transport in the semiconductor silicon to enhance the speed and design of integrated circuits for spintronics.

Two Dartmouth researchers have determined that the element chromium displays electrical properties of magnets in surprising ways. This finding can be used in the emerging field of "spintronics," which might someday contribute to new and more energy efficient ways of processing and storing data.

"The phenomena that we have discovered are likely to lead to new applications of chromium," says Yeong-Ah Soh, the lead researcher on the paper and an associate professor of physics and astronomy at Dartmouth. She worked on the study with Ravi Kummamuru, a former post-doctoral research associate at Dartmouth now at the University of Illinois at Urbana-Champagne.

In two papers published in the April 11 issue of Science, IBM Fellow Stuart Parkin and colleagues at the IBM Almaden Research Center in San Jose describe both the fundamentals of a technology dubbed "racetrack" memory as well as a milestone in that technology. This milestone could lead to electronic devices capable of storing far more data in the same amount of space than is possible today, with lightning-fast boot times, far lower cost and unprecedented stability and durability.

Within the next ten years, racetrack memory, so named because the data "races" around the wire "track," could lead to solid state electronic devices - with no moving parts, and therefore more durable - capable of holding far more data in the same amount of space than is possible today. For example, this technology could enable a handheld device such as an mp3 player to store around 500,000 songs or around 3,500 movies - 100 times more than is possible today - with far lower cost and power consumption. The devices would not only store vastly more information in the same space, but also require much less power and generate much less heat, and be practically unbreakable; the result: massive amounts of personal storage that could run on a single battery for weeks at a time and last for decades.

Graphene is a nanomaterial combining very simple atomic structure with intriguingly complex and largely unexplored physics. Since its first isolation about four years ago researchers suggested a large number of applications for this material in anticipation of future technological revolutions. In particular, graphene is considered as a potential candidate for replacing silicon in future electronic devices.

Theoretical physicists from the Swiss Federal Institute of Technology in Lausanne (EPFL) and Radboud University of Nijmegen (The Netherlands) performed a virtual crash-test of graphene as a material for future spintronic devices, possible components of future computers. The material successfully passed the test, although, with some reservations.

Scientists at the Naval Research Laboratory (NRL) have generated, modulated and electrically detected a pure spin current in silicon, the semiconductor used most widely in the electronic device industry. Magnetic contacts on the surface of an n-type silicon layer enable generation of a spin current which flows separately from a charge current. The spin orientation is electrically detected as a voltage at a second magnetic contact. The relative magnetizations of these contacts allow full control over the orientation of the spin in the silicon channel. This was accomplished in a lateral transport geometry using lithographic techniques compatible with existing device geometries and fabrication methods.

In a rapid follow-up to their achievement as the first to demonstrate how an electron's spin can be electrically injected, controlled and detected in silicon, electrical engineers from the University of Delaware and Cambridge NanoTech now show that this quantum property can be transported a marathon distance in the world of microelectronics-- through an entire silicon wafer.

The finding confirms that silicon--the workhorse material of present-day electronics--now can be harnessed up for new-age spintronics applications.

US scientists have come up with a new mechanism that would control magnetic memory of the computers to enable more accurately write and store information in the hard drives. The new technology will switch a magnetic nanoparticle without any magnetic field.

The latest research now aims at empowering computers with magneto-resistive random access memory (MRAM). In MRAM, data is stored in magnetic storage elements that consist of two layers; each one is separated by a thin non-magnetic spacer.

read more here (Gizmo Watch)

Now, University of California, Berkeley, physicists have succeeded in measuring the spin of a single atom, moving one step closer to quantum computers and "spintronic" devices built from nanoscale transistors based on atomic spin.

Crommie, UC Berkeley post-doctoral fellow Yossi Yayon and graduate student Victor W. Brar succeeded by creating islands of cobalt atoms on a cold copper substrate (4.8 Kelvin, or -451 degrees Fahrenheit) and sprinkling these islands with atoms of either iron or chromium.

Scientists at the Naval Research Laboratory (NRL) have efficiently injected a current of spin-polarized electrons from a ferromagnetic metal contact into silicon, producing a large electron spin polarization in the silicon. Silicon is by far the most widely used semiconductor in the device industry, and is the basis for modern electronics. This demonstration by NRL scientists is a key enabling step for developing devices which rely on electron spin rather than electron charge, a field known as semiconductor spintronics, and is expected to provide higher performance with lower power consumption and heat dissipation. The complete findings of this study titled, “Electrical spin injection into silicon from a ferromagnetic metal/tunnel barrier contact” are published in the August 2007 issue of Nature Physics.