June 2006

Researchers at the University of Bath have received new funding to investigate how the emerging field of spintronics can be applied to in-chip communications, they announced Friday.

Spintronic techniques are already used in some hard disk drives as a way to increase the density of stored information. Spin control also plays a role in the storage of information in MRAM magnetic memories, and in the manipulation of data in quantum computers, another emerging application of spintronics.

However, the researchers at Bath are interested in applying spintronics to the transmission of information, not its storage or manipulation.

The transistors used in today's microprocessors could run at speeds of up 100GHz if it weren't for the wires connecting them to one another, according to Alain Nogaret, a lecturer in the department of physics at Bath.

As processors run at higher and higher frequencies, wires present an obstacle to electrical signals, rather than an unobstructed path, so the signals quickly fade away, even over short distances: "The limit is not the transistors, but the losses in the electronic signals between transistors or clusters of transistors," Nogaret said.
"One way to cut these losses is to send these signals through microwaves," he said. In that way, the signal loss at 100GHz can be cut to just a couple of decibels per centimeter from 115 decibels per centimeter along a wire, he said.

Nogaret and his team hope to generate those microwaves by applying a theory he published in Physical Review Letters last year, entitled "Electrically induced Raman emission from planar spin oscillator," in which he predicted that radio signals are emitted when the spin of an electron trapped in a magnetic field resonates with that field.

Once the research is complete, Nogaret predicts that it will take another five to 10 years before the technology appears in production chips.

The scientific objective of Nanospin (a European Union-funded project involving information that can be stored on nanoparticles) is to manufacturing and study the behavior of complex magnetic nanoparticles composed of a metallic core and one or more shells of ferromagnetic or antiferromagnetic metals in order to control their magnetic properties (blocking temperature, anisotropy, exchange bias, spin quantum barrier height, etc.). These so-called nano-onions have far-ranging applications in medical nanotechnology, magnetic recording and quantum devices, the University of Leicester said in a statement.

Nanospin's technological objectives are to functionalize the nanoclusters to enable them to be produced as ordered arrays on surfaces and to demonstrate proof of principle in classical and quantum single-particle data storage, the university said.