223 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
Intralandscape differentiation of the local flora in the central part of the Gydansky Peninsula (West Siberian Arctic)
The paper aims to describe Russian approaches to inventory of vascular plants diversity in the Russian Arctic. In the study, the local flora method is used. It provides comparable data for spatial comparisons between different locations. The method includes the study of species distributions within a landscape, therefore the concept of “partial flora” was elaborated. A complex estimate “activeness” allows to assess a species role within the landscape. These theoretical concepts are applied at the local flora of a hardly accessible central part of the Gydansky Peninsula. The local flora numbers 191 vascular plant species. Altogether, 18 habitat types were distinguished with partial floras numbering from 15 to 75 species. The highest alfa-diversity was recorded on steep slopes, many rare species occurred there as well. These habitats occupied less than 10% of the area but provided almost 75% of local flora. Although the morphology of relief was better developed at this locality compare to the others at the Gydansky Peninsula, the intralandscape structure of flora is continuous, showing a low beta-diversity and high similarity of species composition between different habitats. It is explained by a high proportion of “active” species, which occur in many different habitat types. Along the zonal gradient within the Gydansky Peninsula, a decrease of species richness at local flora level was found but no change at partial floras level
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
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