Patents by Inventor Song S. Xue

Song S. Xue 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: 8289746
    Abstract: A memory unit includes a magnetic tunnel junction data cell is electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a write current through the magnetic tunnel junction data cell. A first diode is electrically between the magnetic tunnel junction data cell and the source line and a second diode is electrically between the magnetic tunnel junction data cell and the source line. The first diode and second diode are in parallel electrical connection, and having opposing forward bias directions. The memory unit is configured to be precharged to a specified precharge voltage level and the precharge voltage is less than a threshold voltage of the first diode and second diode.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: October 16, 2012
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Hongyue Liu, Yong Lu, Song S. Xue
  • Patent number: 8243503
    Abstract: The present invention relates to a memory cell including a first reference layer having a first magnetization with a first magnetization direction and a second reference layer having a second magnetization with a second magnetization direction substantially perpendicular to the first magnetization direction. A storage layer is disposed between the first reference layer and second reference layer and has a third magnetization direction about 45° from the first magnetization direction and about 135° from the second magnetization direction when the memory cell is in a first data state, and a fourth magnetization direction opposite the third magnetization direction when the memory cell is in a second data state.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: August 14, 2012
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi, Yiming Shi, Song S. Xue, Sining Mao
  • Patent number: 8223560
    Abstract: An apparatus includes at least one memory device including a floating gate element and a magnetic field generator that operably applies a magnetic field to the memory device. The magnetic field directs electrons in the memory device into the floating gate element.
    Type: Grant
    Filed: April 28, 2011
    Date of Patent: July 17, 2012
    Assignee: Seagate Technology LLC
    Inventors: Insik Jin, Yang Li, Hongyue Liu, Song S. Xue
  • Patent number: 8218356
    Abstract: Spin torque magnetic memory elements that have a pinned layer, two free layers, and a current-blocking insulating layer proximate to at least one of the free layers. The resistive state (e.g., low resistance or high resistance) of the memory elements is altered by passing electric current through the element in one direction. In other words, to change from a low resistance to a high resistance, the direction of electric current is the same as to change from a high resistance to a low resistance. The elements have a unidirectional write scheme.
    Type: Grant
    Filed: June 7, 2010
    Date of Patent: July 10, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Dexin Wang, Dimitar V. Dimitrov, Paul E. Anderson, Song S. Xue
  • Patent number: 8203870
    Abstract: An apparatus and associated method for a non-volatile memory cell, such as a multi-bit magnetic random access memory cell. In accordance with various embodiments, a first magnetic tunnel junction (MTJ) is adjacent to a second MTJ having a magnetic filter. The first MTJ is programmed to a first logical state with a first magnetic flux while the magnetic filter absorbs the first magnetic flux to prevent the second MTJ from being programmed.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: June 19, 2012
    Assignee: Seagate Technology LLC
    Inventors: Nurul Amin, Dimitar V. Dimitrov, Haiwen Xi, Song S. Xue
  • Patent number: 8203871
    Abstract: Spin torque magnetic logic devices that function as memory devices and that can be reconfigured or reprogrammed as desired. In some embodiments, the logic device is a single magnetic element, having a pinned layer, a free layer, and a barrier layer therebetween, or in other embodiments, the logic device has two magnetic elements in series. Two input currents can be applied through the element to configure or program the element. In use, logic input data, such as current, is passed through the programmed element, defining the resistance across the element and the resulting logic output. The magnetic logic device can be used for an all-function-in-one magnetic chip.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: June 19, 2012
    Assignee: Seagate Technology LLC
    Inventors: Xiaohua Lou, Dimitar V. Dimitrov, Song S. Xue
  • Publication number: 20120134200
    Abstract: Method and apparatus for writing data to a magnetic memory element, such as a spin-torque transfer random access memory (STRAM) memory cell. In accordance with various embodiments, a multi-level cell (MLC) magnetic memory cell stack has first and second magnetic memory elements connected to a first control line and a switching device connected to a second control line. The first memory element is connected in parallel with the second memory element, and the first and second memory elements are connected in series with the switching device. The first and second memory elements are further disposed at different non-overlapping elevations within the stack. Programming currents are passed between the first and second control lines to concurrently set the first and second magnetic memory elements to different programmed resistances.
    Type: Application
    Filed: November 29, 2010
    Publication date: May 31, 2012
    Applicant: Seagate Technology LLC
    Inventors: Antoine Khoueir, Zheng Gao, Song S. Xue
  • Patent number: 8188558
    Abstract: In order to increase an efficiency of spin transfer and thereby reduce the required switching current, a current perpendicular to plane (CPP) magnetic element for a memory device includes either one or both of a free magnetic layer, which has an electronically reflective surface, and a permanent magnet layer, which has perpendicular anisotropy to bias the free magnetic layer.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: May 29, 2012
    Assignee: Seagate Technology LLC
    Inventors: Dexin Wang, Dimitar V. Dimitrov, Song S. Xue, Insik Jin
  • Publication number: 20120127786
    Abstract: An apparatus and associated method for a non-volatile memory cell, such as a multi-bit magnetic random access memory cell. In accordance with various embodiments, a first magnetic tunnel junction (MTJ) is adjacent to a second MTJ having a magnetic filter. The first MTJ is programmed to a first logical state with a first magnetic flux while the magnetic filter absorbs the first magnetic flux to prevent the second MTJ from being programmed.
    Type: Application
    Filed: November 23, 2010
    Publication date: May 24, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Nurul Amin, Dimitar V. Dimitrov, Haiwen Xi, Song S. Xue
  • Patent number: 8179716
    Abstract: Spin torque magnetic logic device having at least one input element and an output element. Current is applied through the input element(s), and the resulting resistance or voltage across the output element is measured. The input element(s) include a free layer and the output element includes a free layer that is electrically connected to the free layer of the input element. The free layers of the input element and the output element may be electrically connected via magnetostatic coupling, or may be physically coupled. In some embodiments, the output element may have more than one free layer.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: May 15, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Yang Li, Song S. Xue
  • Publication number: 20120104348
    Abstract: Methods for making a programmable metallization memory cell are disclosed.
    Type: Application
    Filed: January 11, 2012
    Publication date: May 3, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Haiwen Xi, Ming Sun, Dexin Wang, Shuiyuan Huang, Michael Tang, Song S. Xue
  • Patent number: 8147995
    Abstract: A bit patterned media (BPM) includes many magnetic dots arranged in tracks on a substrate. The magnetic dots each have a hard magnetic core, a soft magnetic cladding surrounding the core and a thin non-magnetic layer that separates the hard magnetic core from the soft magnetic ring. The soft magnetic cladding stabilizes the magnetization at the edges of the hard magnetic core to improve the signal to noise ratio of the magnetic dots. The soft magnetic rings also narrow the magnetic field of the dots which reduces the space requirements and allows more dots to be placed on the substrate.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: April 3, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Kaizhong Gao, Song S. Xue
  • Publication number: 20120069630
    Abstract: Write verify methods for resistance random access memory (RRAM) are provided. The methods include applying a reset operation voltage pulse across a RRAM cell to change a resistance of the RRAM cell from a low resistance state to a high resistance state and applying a forward resetting voltage pulse across the RRAM cell if the RRAM cell has a high resistance state resistance value less than a selected lower resistance limit value. The method also includes applying a reverse resetting voltage pulse across the RRAM cell if the RRAM cell has a high resistance state resistance values is greater than a selected upper resistance limit value. The reverse resetting voltage pulse has a second polarity being opposite the first polarity.
    Type: Application
    Filed: October 21, 2011
    Publication date: March 22, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Haiwen Xi, Song S. Xue
  • Publication number: 20120061783
    Abstract: Magnetic tunnel junction cells and methods of making magnetic tunnel junction cells that include a radially protective layer extending proximate at least the ferromagnetic free layer of the cell. The radially protective layer can be specifically chosen in thickness, deposition method, material composition, and/or extent along the cell layers to enhance the effective magnetic properties of the free layer, including the effective coercivity, effective magnetic anisotropy, effective dispersion in magnetic moment, or effective spin polarization.
    Type: Application
    Filed: October 21, 2011
    Publication date: March 15, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Paul E. Anderson, Song S. Xue
  • Patent number: 8102691
    Abstract: Magnetic shift registers in which data writing and reading is accomplished by moving the magnetic domain walls by electric current. Various embodiments of domain wall nodes or anchors that stabilize a domain wall are provided. In some embodiments, the wall anchors are elements separate from the magnetic track. In other embodiments, the wall anchors are disturbances in the physical configuration of the magnetic track. In still other embodiments, the wall anchors are disturbances in the material of the magnetic track.
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: January 24, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Xiaobin Wang, Dimitar V. Dimitrov, Paul E. Anderson, Harry Liu, Song S. Xue, Andreas Roelofs, Markus Siegert
  • Patent number: 8098538
    Abstract: Method and apparatus for using a uni-directional write current to store different logic states in a non-volatile memory cell, such as a modified STRAM cell. In some embodiments, the memory cell has an unpinned ferromagnetic reference layer adjacent a cladded conductor, a ferromagnetic storage layer and a tunneling barrier between the reference layer and the storage layer. Passage of a current along the cladded conductor induces a selected magnetic orientation in the reference layer, which is transferred through the tunneling barrier for storage by the storage layer. Further, the orientation of the applying step is provided by a cladding layer adjacent a conductor along which a current is passed and the current induces a magnetic field in the cladding layer of the selected magnetic orientation.
    Type: Grant
    Filed: May 4, 2011
    Date of Patent: January 17, 2012
    Assignee: Seagate Technology LLC
    Inventors: Daniel Seymour Reed, Yong Lu, Song S. Xue, Dimitar V. Dimitrov, Paul E. Anderson
  • Patent number: 8097902
    Abstract: A programmable metallization memory cell that has an apertured insulating layer comprising at least one aperture therethrough positioned between the active electrode and the inert electrode. Superionic clusters are present within the at least one aperture, and may extend past the at least one aperture. Also, methods for making a programmable metallization memory cell are disclosed.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: January 17, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Ming Sun, Dexin Wang, Shuiyuan Huang, Michael Tang, Song S. Xue
  • Patent number: 8091209
    Abstract: A magnetic sensor includes a sensor stack having a first magnetic portion, a second magnetic portion, and a barrier layer between the first magnetic portion and the second magnetic portion. The first magnetic portion and/or the second magnetic portion comprises a multilayer structure including a first magnetic layer having a positive magnetostriction adjacent to the barrier layer, a second magnetic layer, and an intermediate layer between the first magnetic layer and the second magnetic layer. The magnetic sensor exhibits a magnetoresistive ratio of at least about 62% with a resistance-area (RA) product of about 0.45 ?·?m2.
    Type: Grant
    Filed: October 3, 2007
    Date of Patent: January 10, 2012
    Assignee: Seagate Technology LLC
    Inventors: Zheng Gao, Dimitar V. Dimitrov, Song S. Xue
  • Patent number: 8069492
    Abstract: A spin-torque probe microscope and methods of using the same are described. The spin-torque probe microscope includes a cantilever probe body, a magnetic tip disposed at a distal end of the cantilever probe body, an electrically conductive sample disposed proximate to the magnetic tip, an electrical circuit providing a spin-polarized electron current to the electrically conductive sample, and a vibration detection element configured to sense vibration frequency of the cantilever probe body. The spin-polarized electron current is sufficient to alter a local electron spin or magnetic moment within the electrically conductive sample and be sensed by the magnetic tip.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: November 29, 2011
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Song S. Xue
  • Patent number: 8059450
    Abstract: Write verify methods for resistance random access memory (RRAM) are provided. The methods include applying a reset operation voltage pulse across a RRAM cell to change a resistance of the RRAM cell from a low resistance state to a high resistance state. Then the method includes applying a forward resetting voltage pulse across the RRAM cell if the RRAM cell has a high resistance state resistance value less than a selected lower resistance limit value. This step is repeated until the high resistance state resistance value is greater than the lower resistance limit value. The method also includes applying a reverse resetting voltage pulse across the RRAM cell if the RRAM cell has a high resistance state resistance values is greater than a selected upper resistance limit value. The reverse resetting voltage pulse has a second polarity being opposite the first polarity. This step is repeated until all the high resistance state resistance value is less than the upper resistance limit value.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: November 15, 2011
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Song S. Xue