3,144 research outputs found
Magnetic Cellular Nonlinear Network with Spin Wave Bus for Image Processing
We describe and analyze a cellular nonlinear network based on magnetic
nanostructures for image processing. The network consists of magneto-electric
cells integrated onto a common ferromagnetic film - spin wave bus. The
magneto-electric cell is an artificial two-phase multiferroic structure
comprising piezoelectric and ferromagnetic materials. A bit of information is
assigned to the cell's magnetic polarization, which can be controlled by the
applied voltage. The information exchange among the cells is via the spin waves
propagating in the spin wave bus. Each cell changes its state as a combined
effect of two: the magneto-electric coupling and the interaction with the spin
waves. The distinct feature of the network with spin wave bus is the ability to
control the inter-cell communication by an external global parameter - magnetic
field. The latter makes possible to realize different image processing
functions on the same template without rewiring or reconfiguration. We present
the results of numerical simulations illustrating image filtering, erosion,
dilation, horizontal and vertical line detection, inversion and edge detection
accomplished on one template by the proper choice of the strength and direction
of the external magnetic field. We also present numerical assets on the major
network parameters such as cell density, power dissipation and functional
throughput, and compare them with the parameters projected for other
nano-architectures such as CMOL-CrossNet, Quantum Dot Cellular Automata, and
Quantum Dot Image Processor. Potentially, the utilization of spin waves
phenomena at the nanometer scale may provide a route to low-power consuming and
functional logic circuits for special task data processing
Spin Wave Magnetic NanoFabric: A New Approach to Spin-based Logic Circuitry
We propose and describe a magnetic NanoFabric which provides a route to
building reconfigurable spin-based logic circuits compatible with conventional
electron-based devices. A distinctive feature of the proposed NanoFabric is
that a bit of information is encoded into the phase of the spin wave signal. It
makes possible to transmit information without the use of electric current and
utilize wave interference for useful logic functionality. The basic elements
include voltage-to-spin wave and wave-to-voltage converters, spin waveguides, a
modulator, and a magnetoelectric cell. As an example of a magnetoelectric cell,
we consider a two-phase piezoelectric-piezomagnetic system, where the spin wave
signal modulation is due to the stress-induced anisotropy caused by the applied
electric field. The performance of the basic elements is illustrated by
experimental data and results of numerical modeling. The combination of the
basic elements let us construct magnetic circuits for NOT and Majority logic
gates. Logic gates AND, OR, NAND and NOR are shown to be constructed as the
combination of NOT and a reconfigurable Majority gates. The examples of
computational architectures such as Cellular Automata, Cellular Nonlinear
Network and Field Programmable Gate Array are described. The main advantage of
the proposed NanoFabric is in the ability to realize logic gates with less
number of devices than it required for CMOS-based circuits. Potentially, the
area of the elementary reconfigurable Majority gate can be scaled down to
0.1um2. The disadvantages and limitations of the proposed NanoFabric are
discussed
Massively parallel computing on an organic molecular layer
Current computers operate at enormous speeds of ~10^13 bits/s, but their
principle of sequential logic operation has remained unchanged since the 1950s.
Though our brain is much slower on a per-neuron base (~10^3 firings/s), it is
capable of remarkable decision-making based on the collective operations of
millions of neurons at a time in ever-evolving neural circuitry. Here we use
molecular switches to build an assembly where each molecule communicates-like
neurons-with many neighbors simultaneously. The assembly's ability to
reconfigure itself spontaneously for a new problem allows us to realize
conventional computing constructs like logic gates and Voronoi decompositions,
as well as to reproduce two natural phenomena: heat diffusion and the mutation
of normal cells to cancer cells. This is a shift from the current static
computing paradigm of serial bit-processing to a regime in which a large number
of bits are processed in parallel in dynamically changing hardware.Comment: 25 pages, 6 figure
Nanomagnetic Boolean Logic -- The Tempered (and Realistic) Vision
The idea of nanomagnetic Boolean logic was advanced more than two decades
ago. It envisaged the use of nanomagnets with two stable magnetization
orientations as the primitive binary switch for implementing logic gates and
ultimately combinational/sequential circuits. Enthusiastic proclamations of how
nanomagnetic logic will eclipse traditional (transistor-based) logic circuits
proliferated the applied physics literature. Two decades later there is not a
single viable nanomagnetic logic chip in sight, let alone one that is a
commercial success. In this perspective article, I offer my reasons on why this
has come to pass. I present a realistic and tempered vision of nanomagnetic
logic, pointing out many misconceptions about this paradigm, flaws in some
proposals that appeared in the literature, shortcomings, and likely pitfalls
that might stymie progress in this field.Comment: Accepted in IEEE Acces
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