Patents by Inventor Naimul Hassan

Naimul Hassan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11514301
    Abstract: The present disclosure provides a domain wall magnetic tunnel junction device. Integration of input spikes pushes a domain wall within a ferromagnetic track toward a magnetic tunnel junction (MTJ). An energy gradient within the track pushes the domain wall away from the MTJ by leaking accumulated energy from the input spikes. If the integrated input spikes exceed the energy leak of the gradient within a specified time period, the domain wall reaches the MTJ and reverses its resistance, producing an output spike. The leaking energy gradient can be created by a magnetic field, a trapezoidal shape of the ferromagnetic track, or nonuniform material properties in the ferromagnetic track.
    Type: Grant
    Filed: January 29, 2020
    Date of Patent: November 29, 2022
    Assignee: Board of Regents, The University of Texas System
    Inventors: Joseph S. Friedman, Wesley H. Brigner, Naimul Hassan, Xuan Hu
  • Publication number: 20220208242
    Abstract: A magnetic tunnel junction is provided. The magnetic tunnel junction comprises an insulating tunnel barrier and a fixed ferromagnet layer adjacent the tunnel barrier. The fixed ferromagnet comprises a fixed magnetization along an easy axis approximately normal to an interface between the fixed ferromagnet and the tunnel barrier. A free ferromagnet layer is adjacent the tunnel barrier on the side opposite the fixed ferromagnet. The free ferromagnet layer comprises a bistable magnetization along the easy axis that can switch between a parallel state and an anti-parallel state with the fixed ferromagnet. A heavy metal layer is adjacent the free ferromagnet on the side opposite the tunnel barrier. A unidirectional electric current pulse through the heavy metal layer switches the bistable magnetization of the free ferromagnet, thereby switching an electrical resistance state of the magnetic tunnel junction.
    Type: Application
    Filed: April 30, 2020
    Publication date: June 30, 2022
    Inventors: Joseph S. Friedman, Naimul Hassan
  • Publication number: 20210232903
    Abstract: The present disclosure provides a domain wall magnetic tunnel junction device. Integration of input spikes pushes a domain wall within a ferromagnetic track toward a magnetic tunnel junction (MTJ). An energy gradient within the track pushes the domain wall away from the MTJ by leaking accumulated energy from the input spikes. If the integrated input spikes exceed the energy leak of the gradient within a specified time period, the domain wall reaches the MTJ and reverses its resistance, producing an output spike. The leaking energy gradient can be created by a magnetic field, a trapezoidal shape of the ferromagnetic track, or nonuniform material properties in the ferromagnetic track. A feedback and feedforward crossbar configuration is disclosed that provides for a neuromorphic computing system suitable for unsupervised learning.
    Type: Application
    Filed: March 24, 2021
    Publication date: July 29, 2021
    Inventors: Joseph S. Friedman, Wesley H. Brigner, Naimul Hassan, Xuan Hu, Alvaro Velasquez
  • Publication number: 20200242462
    Abstract: The present disclosure provides a domain wall magnetic tunnel junction device. Integration of input spikes pushes a domain wall within a ferromagnetic track toward a magnetic tunnel junction (MTJ). An energy gradient within the track pushes the domain wall away from the MTJ by leaking accumulated energy from the input spikes. If the integrated input spikes exceed the energy leak of the gradient within a specified time period, the domain wall reaches the MTJ and reverses its resistance, producing an output spike. The leaking energy gradient can be created by a magnetic field, a trapezoidal shape of the ferromagnetic track, or nonuniform material properties in the ferromagnetic track.
    Type: Application
    Filed: January 29, 2020
    Publication date: July 30, 2020
    Inventors: Joseph S. Friedman, Wesley H. Brigner, Naimul Hassan, Xuan Hu