skip to main content

Search for: All records

Creators/Authors contains: "Xiao, T. Patrick"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Abstract Topological solitons are exciting candidates for the physical implementation of next-generation computing systems. As these solitons are nanoscale and can be controlled with minimal energy consumption, they are ideal to fulfill emerging needs for computing in the era of big data processing and storage. Magnetic domain walls (DWs) and magnetic skyrmions are two types of topological solitons that are particularly exciting for next-generation computing systems in light of their non-volatility, scalability, rich physical interactions, and ability to exhibit non-linear behaviors. Here we summarize the development of computing systems based on magnetic topological solitons, highlighting logical and neuromorphic computing with magnetic DWs and skyrmions. 
    more » « less
    Free, publicly-accessible full text available May 25, 2024
  2. null (Ed.)
    The domain wall-magnetic tunnel junction (DW-MTJ) is a spintronic device that enables efficient logic circuit design because of its low energy consumption, small size, and non-volatility. Furthermore, the DW-MTJ is one of the few spintronic devices for which a direct cascading mechanism is experimentally demonstrated without any extra buffers; this enables potential design and fabrication of a large-scale DW-MTJ logic system. However, DW-MTJ logic relies on the conversion between electrical signals and magnetic states which is sensitive to process imperfection. Therefore, it is important to analyze the robustness of such DW-MTJ devices to anticipate the system reliability before fabrication. Here we propose a new DW-MTJ model that integrates the impacts of process variation to enable the analysis and optimization of DW-MTJ logic. This will allow circuit and device design that enhances the robustness of DW-MTJ logic and advances the development of energy-efficient spintronic computing systems. 
    more » « less
  3. Abstract

    In neuromorphic computing, artificial synapses provide a multi‐weight (MW) conductance state that is set based on inputs from neurons, analogous to the brain. Herein, artificial synapses based on magnetic materials that use a magnetic tunnel junction (MTJ) and a magnetic domain wall (DW) are explored. By fabricating lithographic notches in a DW track underneath a single MTJ, 3–5 stable resistance states that can be repeatably controlled electrically using spin‐orbit torque are achieved. The effect of geometry on the synapse behavior is explored, showing that a trapezoidal device has asymmetric weight updates with high controllability, while a rectangular device has higher stochasticity, but with stable resistance levels. The device data is input into neuromorphic computing simulators to show the usefulness of application‐specific synaptic functions. Implementing an artificial neural network (NN) applied to streamed Fashion‐MNIST data, the trapezoidal magnetic synapse can be used as a metaplastic function for efficient online learning. Implementing a convolutional NN for CIFAR‐100 image recognition, the rectangular magnetic synapse achieves near‐ideal inference accuracy, due to the stability of its resistance levels. This work shows MW magnetic synapses are a feasible technology for neuromorphic computing and provides design guidelines for emerging artificial synapse technologies.

    more » « less