36 research outputs found
Multi-Frequency Magnonic Logic Circuits for Parallel Data Processing
We describe and analyze magnonic logic circuits enabling parallel data
processing on multiple frequencies. The circuits combine bi-stable (digital)
input/output elements and an analog core. The data transmission and processing
within the analog part is accomplished by the spin waves, where logic 0 and 1
are encoded into the phase of the propagating wave. The latter makes it
possible to utilize a number of bit carrying frequencies as independent
information channels. The operation of the magnonic logic circuits is
illustrated by numerical modeling. We also present the estimates on the
potential functional throughput enhancement and compare it with scaled CMOS.
The described multi-frequency approach offers a fundamental advantage over the
transistor-based circuitry and may provide an extra dimension for the Moor's
law continuation. The shortcoming and potentials issues are also discussed
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
Magnonic Combinatorial Memory
In this work, we consider a type of magnetic memory where information is
encoded into the mutual arrangements of magnets. The device is an active ring
circuit comprising magnetic and electronic parts connected in series. The
electric part includes a broad-band amplifier, phase shifters, and attenuators.
The magnetic part is a mesh of magnonic waveguides with magnets placed on the
waveguide junctions. There are amplitude and phase conditions for
auto-oscillations to occur in the active ring circuit. The frequency(s) of the
auto-oscillation and spin wave propagation route(s) in the magnetic part
depends on the mutual arrangement of magnets in the mesh. The propagation route
is detected with a set of power sensors. The correlation between circuit
parameters and spin wave route is the base of memory operation. The combination
of input/output switches connecting electric and magnetic parts, and electric
phase shifters constitute the memory address. The output of power sensors is
the memory state. We present experimental data on the proof-of-the-concept
experiments on the prototype with just three magnets placed on top of a
single-crystal yttrium iron garnet Y3Fe2(FeO4)3 (YIG) film. The results
demonstrate a robust operation with On/Off ratio for route detection exceeding
35 dB at room temperature. The number of propagation routes scales factorial
with the size of the magnetic part. Coding information in propagation routes
makes it possible to drastically increase the data storage density compared to
conventional memory devices. MCM with just 25 magnets can store as much as 25!
(10 Yotta) bits. Physical limits and constraints are also discussed
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
Non-Volatile Magnonic Logic Circuits Engineering
We propose a concept of magnetic logic circuits engineering, which takes an
advantage of magnetization as a computational state variable and exploits spin
waves for information transmission. The circuits consist of magneto-electric
cells connected via spin wave buses. We present the result of numerical
modeling showing the magneto-electric cell switching as a function of the
amplitude as well as the phase of the spin wave. The phase-dependent switching
makes it possible to engineer logic gates by exploiting spin wave buses as
passive logic elements providing a certain phase-shift to the propagating spin
waves. We present a library of logic gates consisting of magneto-electric cells
and spin wave buses providing 0 or p phase shifts. The utilization of phases in
addition to amplitudes is a powerful tool which let us construct logic circuits
with a fewer number of elements than required for CMOS technology. As an
example, we present the design of the magnonic Full Adder Circuit comprising
only 5 magneto-electric cells. The proposed concept may provide a route to more
functional wave-based logic circuitry with capabilities far beyond the limits
of the traditional transistor-based approach