Patents by Inventor Mark J. Higgins

Mark J. Higgins 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).

  • Piezo-noise microscope and methods for use thereof
    Publication number: 20030234358
    Abstract: A piezo-noise microscope for use in examining a sample of piezoelectric material is provided. The piezo-noise microscope improves on existing atomic force microscope (AFM) techniques by generating piezoresponse noise signals which are useful for determining the long-term polarization stability of piezoelectric materials, and in particular ferroelectric materials, without the need to make repeated observations over extended periods of time. A method for detecting piezo-response noise in a sample of piezoelectric material using a piezo-noise microscope, and a method for detecting the stability of polarization in regions of a sample of piezoelectric material, are also provided.
    Type: Application
    Filed: July 31, 2002
    Publication date: December 25, 2003
    Applicant: NEC Research Institute, Inc.
    Inventors: Mark J. Higgins, Sabyasachi Bhattacharya, Ajit Krishnan
  • Scanning AC hall microscope
    Patent number: 6396261
    Abstract: A scanning AC hall microscope and a method which measures the domain pattern of magnetic materials, such as magnetic storage media, by measuring the oscillatory motion of a domain boundary under the influence of an external applied AC magnetic field, which allows a differentiation between domains which are immobile and domains which are mobile.
    Type: Grant
    Filed: March 20, 2000
    Date of Patent: May 28, 2002
    Assignee: NEC Research Institute, Inc.
    Inventors: Maxim Martchevskii, Mark J. Higgins, Sabyasachi Bhattacharya
  • Reduction of imprint in ferroelectric devices using a depoling technique
    Patent number: 6392919
    Abstract: A method for reducing imprint in a ferroelectric device which includes the steps of: applying a signal having a bipolar pulse shape for a predetermined time to the ferroelectric device; and decreasing the signal amplitude gradually in predetermined intervals of time and amplitude. Preferably, the bipolar shape signal is a sinusoidal wave, a square wave, or a sawtooth wave and the ferroelectric device is a capacitor of a memory cell in a computer. Also provided is an apparatus for reducing imprint in a ferroelectric device.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: May 21, 2002
    Assignee: NEC Research Institute, Inc.
    Inventors: Mark J. Higgins, Ajit Krishnan, Sabyasachi Bhattacharya, Michael M. J. Treacy
  • Reduction of imprint in ferroelectric devices using a depoling technique
    Patent number: 6294393
    Abstract: A method for reducing imprint in a ferroelectric device which includes the steps of: applying a signal having a bipolar pulse shape for a predetermined time to the ferroelectric device; and decreasing the signal amplitude gradually in predetermined intervals of time and amplitude. Preferably, the bipolar shape signal is a sinusoidal wave, a square wave, or a sawtooth wave and the ferroelectric device is a capacitor or a memory cell in a computer. Also provided is an apparatus for reducing imprint in a ferroelectric device.
    Type: Grant
    Filed: August 23, 2000
    Date of Patent: September 25, 2001
    Assignee: NEC Research Institute, Inc.
    Inventors: Mark J. Higgins, Ajit Krishnan, Sabyasachi Bhattacharya, Michael M. J. Treacy
  • Switch useful at superconducting temperatures and comprising superconducting material
    Patent number: 6184765
    Abstract: The present invention is directed, inter alia, to a switch comprising: (A) a superconducting material whose field cooled and zero field cooled ac permittivities differ from each other, and whose field cooled and zero field cooled ac susceptibilities differ from each other, in a range of temperature below the superconducting transition temperature of the material; (B) means for applying a static magnetic field to said material; (C) means for controllably applying to said material an oscillating magnetic field of a magnitude effective to convert said material from a state exhibiting filed cooled permittivity to a state exhibiting zero field cooled permittivity; and (D) means for applying to said material a heat pulse effective to convert said material from a state exhibiting zero field cooled permittivity to a state exhibiting field cooled permittivity, said switch operating between a superconducting zero field cooled state and a superconducting field cooled state.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: February 6, 2001
    Assignees: NEC Research Institute, Inc., Tata Institute of Fundamental Research, TPPED (Technical Pyhsics & Prototype Engineering Division)
    Inventors: Sabyasachi Bhattacharya, Mark J. Higgins, Satyajit S. Banerjee, Nitin Patil, Srinivasan Ramakrishnan, Arun K. Grover, Chandrasekhar V.R. Turumella, Vinod C. Sahni, Gurazada Ravikumar, Prashant K. Mishra