31 research outputs found
Investigation into MQCA based low power Digital logic Design Methodology
The use of the phenomenon of magnetism for information processing goes back to the end of XIX century. In 1888,
Oberlin Smith suggested the use of permanent magnetic impressions for the recording of sound. The recording of the human voice on a steel piano wire was first carried out in 1898 by a Danish inventor Valdemar Poulsen, whose invention
gave rise some 30 years later to a magnetic tape recording industry
Experimental demonstration of an integrated on-chip p-bit core utilizing stochastic Magnetic Tunnel Junctions and 2D-MoS FETs
Probabilistic computing is a novel computing scheme that offers a more
efficient approach than conventional CMOS-based logic in a variety of
applications ranging from optimization to Bayesian inference, and invertible
Boolean logic. The probabilistic-bit (or p-bit, the base unit of probabilistic
computing) is a naturally fluctuating entity that requires tunable
stochasticity; by coupling low-barrier stochastic Magnetic Tunnel Junctions
(MTJs) with a transistor circuit, a compact implementation is achieved. In this
work, through integrating stochastic MTJs with 2D-MoS FETs, the first
on-chip realization of a key p-bit building block displaying
voltage-controllable stochasticity is demonstrated. In addition, supported by
circuit simulations, this work provides a careful analysis of the three
transistor-one magnetic tunnel junction (3T-1MTJ) p-bit design, evaluating how
the characteristics of each component influence the overall p-bit output. This
understanding of the interplay between the characteristics of the transistors
and the MTJ is vital for the construction of a fully functioning p-bit, making
the design rules presented in this article key for future experimental
implementations of scaled on-chip p-bit networks
Information Processing with Electron Spins
Information processors process information in a variety of ways. The human brain processes information through a highly interconnected system of neurons and synapses, while a digital computer processes information by having a binary switch toggle on and off in response to a stream of binary bits. The “switch” is the most primitive unit of the modern computer. The better it is (faster, more energy efficient, more reliable, etc.), the more advanced is the computer hardware. Energy efficiency, however, is more important than any other attribute, not so much because energy is costly, but because too much energy dissipation prevents increasing the density of switches on a chip that is necessary to make the chip increasingly more powerful. Reducing dissipation entails radically new and often revolutionary approaches for implementing the switch. One such approach is to encode digital bit information in the spin polarization of a single electron (or ensemble of electrons) and then using two mutually antiparallel polarizations to represent the binary bits 0 and 1. Switching between the bits can be accomplished by simply flipping the polarizations of the spins, which takes very little energy. Such switches are extremely energy efficient if designed properly, but they are somewhat slower than traditional transistor-based switches and can be more error prone. This paper discusses the pros and cons of spin-based switches and introduces the reader to the most recent advancements in information processing predicated on encoding information in electron spin polarization
Wave Pipelining for Majority-based Beyond-CMOS Technologies
The performance of some emerging nanotechnolo- gies benefits from wave pipelining. The design of such circuits re- quires new models and algorithms. Thus we show how Majority- Inverter Graphs (MIG) can be used for this purpose and we extend the related optimization algorithms. The resulting designs have increased throughput, something that has traditionally been a weak point for the majority of non-charge-based technologies. We benchmark the algorithm on MIG netlists with three different technologies, Spin Wave Devices (SWD), Quantum-dot Cellular Automata (QCA), and NanoMagnetic Logic (NML). We find that the wave pipelined version of the netlists have an improvement in throughput over power of 23×, 13×, and 5× for SWD, QCA, and NML, respectively. In terms of throughput over area ratio, the improvement is 5×, 8×, and 3×, respectively