6,436 research outputs found
Importance sampling for thermally induced switching and non-switching probabilities in spin-torque magnetic nanodevices
Spin-transfer torque magnetoresistive random access memory is a potentially
transformative technology in the non-volatile memory market. Its viability
depends, in part, on one's ability to predictably induce or prevent switching;
however, thermal fluctuations cause small but important errors in both the
writing and reading processes. Computing these very small probabilities for
magnetic nanodevices using naive Monte Carlo simulations is essentially
impossible due to their slow statistical convergence, but variance reduction
techniques can offer an effective way to improve their efficiency. Here, we
provide an illustration of how importance sampling can be efficiently used to
estimate low read and write soft error rates of macrospin and coupled-spin
systems.Comment: 11 pages, 14 figure
All-optical control of ferromagnetic thin films and nanostructures
The interplay of light and magnetism has been a topic of interest since the
original observations of Faraday and Kerr where magnetic materials affect the
light polarization. While these effects have historically been exploited to use
light as a probe of magnetic materials there is increasing research on using
polarized light to alter or manipulate magnetism. For instance deterministic
magnetic switching without any applied magnetic fields using laser pulses of
the circular polarized light has been observed for specific ferrimagnetic
materials. Here we demonstrate, for the first time, optical control of
ferromagnetic materials ranging from magnetic thin films to multilayers and
even granular films being explored for ultra-high-density magnetic recording.
Our finding shows that optical control of magnetic materials is a much more
general phenomenon than previously assumed. These results challenge the current
theoretical understanding and will have a major impact on data memory and
storage industries via the integration of optical control of ferromagnetic
bits.Comment: 21 pages, 11 figure
Design of Adiabatic MTJ-CMOS Hybrid Circuits
Low-power designs are a necessity with the increasing demand of portable
devices which are battery operated. In many of such devices the operational
speed is not as important as battery life. Logic-in-memory structures using
nano-devices and adiabatic designs are two methods to reduce the static and
dynamic power consumption respectively. Magnetic tunnel junction (MTJ) is an
emerging technology which has many advantages when used in logic-in-memory
structures in conjunction with CMOS. In this paper, we introduce a novel
adiabatic hybrid MTJ/CMOS structure which is used to design AND/NAND, XOR/XNOR
and 1-bit full adder circuits. We simulate the designs using HSPICE with 32nm
CMOS technology and compared it with a non-adiabatic hybrid MTJ/CMOS circuits.
The proposed adiabatic MTJ/CMOS full adder design has more than 7 times lower
power consumtion compared to the previous MTJ/CMOS full adder
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