May 08, 2006 |
Development of three highly interconnected nanoscale architectures using spin-wave technology
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(Nanowerk News) Engineers at the UCLA Henry Samueli
School of Engineering and Applied Science are announcing a critical
new breakthrough in semiconductor spin-wave research.
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UCLA Engineering adjunct professor Mary Mehrnoosh Eshaghian-Wilner,
researcher Alexander Khitun and professor Kang Wang have created
three novel nanoscale computational architectures using a technology
they pioneered called “spin-wave buses” as the mechanism
for interconnection. The three nanoscale architectures are not
only power efficient, but also possess a high degree of interconnectivity. |
“Progress in the miniaturization of semiconductor electronic
devices has meant chip features have become nanoscale. Today’s
current devices, which are based on complementary metal oxide
semiconductor standards, or ‘CMOS,’ can’t get
much smaller and still function properly and effectively. CMOS
continues to face increasing power and cost challenges,”
Wang said. |
In contrast to traditional information processing technology
devices that simply move electric charges around while ignoring
the extra spin that tags along for the ride, spin-wave buses put
the extra motion to work transferring data or power between computer
components. Information is encoded directly into the phase of
the spin waves. Unlike a point-to-point connection, a “bus”
can logically connect several peripherals. The result is a reduction
in power consumption, less heat and, ultimately, the ability to
make components much smaller as no physical wires are actually
used to send the data. |
“Design of nanoscale architectures for computing is a very
new area, but an important one for the future. In order to produce
effective nanoscale devices, we need to actively look at new low
power designs that can have efficient interconnectivity and allow
scaling beyond current barriers,” Eshaghian-Wilner said. |
The idea of using spin waves for information transmission and
processing was first developed under the name “spin-wave
buses” by UCLA Engineering’s Khitun, Wang and graduate
researcher Roman Ostroumov.
“We’ve made a significant effort to demonstrate the
operation of spin-based devices at room temperature,” Khitun
said. “Our experimental results confirm the intriguing fact
that information can be transmitted via spin waves propagating
in spin waveguides — ferromagnetic films.” |
The innovative work with spin-wave buses recently garnered the
trio a prestigious 2006 Inventor Recognition Award from the Microelectronics
Advanced Research Corp. The corporation funds and operates university-based
research centers in microelectronics technology, seeking to expand
cooperative, long-range applied microelectronics research at U.S.
universities. |
UCLA Engineering’s team contends that the creation and
detection of spin-wave packets in nanostructures can be used efficiently
to perform massively parallel computational operations, allowing
for the design of the first practical, fully interconnected network
of processors on a single chip. This breaks with currently proposed
spintronic architectures, which rely on a charge transfer for
information exchange and show significant interconnect problems. |
Eshaghian-Wilner, in conjunction with Khitun and Wang, has developed
three innovative, spin-wave bus-based designs that use spin waves
to achieve the low-power device performance and improved scalability
highly desired by industry chip manufacturers. |
The first device developed by UCLA engineers, described in a
paper presented publicly at the annual ACM International Conference
on Computing Frontiers, being held in Ischia, Italy, during the
first week of May, is a reconfigurable mesh interconnected with
spin-wave buses. The architecture of the device requires the same
number of switches and buses as standard reconfigurable meshes,
but is capable of simultaneously transmitting multiple waves using
different frequencies on each of the spin-wave buses — making
the parallel architecture capable of very fast and fault-tolerant
algorithms. Unlike the traditional spin-based nanostructures that
transmit charge, with this design only waves are transmitted,
keeping power consumption extremely low. |
“This innovative design represents an original
approach for nanoscale computational devices while preserving
all of the advantages of wave-based computing,” Eshaghian-Wilner
said. |
The second architecture invention, details of
which will be published at the Nano Science and Technology Institute
9th Annual Nanotechnology Conference and Trade Show — or
Nanotech 2006 — being held in Boston during the second week
of May, is a fully connected cluster of functional units with
spin-wave buses. Each node simultaneously broadcasts to all other
nodes, and can receive and process multiple data concurrently.
The novel design allows all nodes to intercommunicate in constant
time. This invention overcomes traditional area restrictions found
in current networks. |
The researchers also have developed a spin-wave-based
crossbar for fully interconnecting multiple inputs to multiple
outputs, and plan to announce the full details of the design at
the 2006 IEEE Conference on Nanotechnology to be held in Cincinnati,
Ohio, this coming July. As compared to standard molecular crossbar
designs, UCLA Engineering’s is much more fault-tolerant
— allowing alternate paths to be reconfigured in case of
switch failure. By transmitting waves instead of traditional current
charge transmission, the design architecture allows a large reduction
in power consumption and provides a high level of interconnectivity
between many more paths than currently possible. |
“We’re tremendously excited about
the future of this research,” Eshaghian-Wilner said. “The
designs demonstrate outstanding performance as interconnects for
massively parallel integrated circuits.” |
“Over the past few years, scientists have
studied a variety of methods for designing nanoscale computer
architectures. Our collaborative approach using spin-wave buses
is a novel one that we hope will lead to additional breakthroughs,”
Khitun added. |
Currently, various extensions and applications
of these three designs are being studied and evaluated by the
UCLA Engineering team and their students. Postgraduate researcher
Shiva Navab is proposing a set of innovative techniques for mapping
biologically inspired types of computations on these models for
image processing and neural computations. Other application areas
being investigated include bioinformatics and implantable biomedical
devices. Heterogeneous integrations of these designs in a complementary
fashion with other molecular and nanotechnologies also are being
developed. |
The architectural methods are undergoing implementation
and further testing at the UCLA Device Research Laboratories by
research scientists Joon Young Lee, who specializes in spin wave
based device processing, and Ming Bao, who carries out the time-resolved
inductive voltage measurements aimed at detecting spin waves propagating
in 100-nanometer-thick ferromagnetic films. The Device Research
Laboratories nano facilities are led by Wang, director of the
Functional Engineered Nano Architectonics Focus Center and the
newly developed Western Institute of Nanotechnology, all headquartered
at the UCLA Henry Samueli School of Engineering and Applied Science.
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