Patents by Inventor Rolf Allenspach
Rolf Allenspach 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).
-
Publication number: 20090308313Abstract: A microelectronic device or non-volatile resistance switching memory comprising the switching material for storing digital information. A process includes a step of depositing the switching material by a CMOS deposition technique at a temperature lower than 400° C.Type: ApplicationFiled: August 13, 2009Publication date: December 17, 2009Applicant: International Business Machines CorporationInventors: Rolf Allenspach, Johannes G. Bednorz, Gerhard Ingmar Meijer, Chung Hon Lam, Richard Stutz, Daniel Widmer
-
Publication number: 20090305487Abstract: A microelectronic device or non-volatile resistance switching memory comprising the switching material for storing digital information. A process includes a step of depositing the switching material by a CMOS deposition technique at a temperature lower than 400° C.Type: ApplicationFiled: August 14, 2009Publication date: December 10, 2009Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Rolf Allenspach, Johannes G. Bednorz, Gerhard Ingmar Meijer, Chung Hon Lam, Richard Stutz, Daniel Widmer
-
Patent number: 7602000Abstract: A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.Type: GrantFiled: November 19, 2003Date of Patent: October 13, 2009Assignee: International Business Machines CorporationInventors: Jonathan Zanhong Sun, Rolf Allenspach, Stuart Stephen Papworth Parkin, John Casimir Slonczewski, Bruce David Terris
-
Patent number: 7336515Abstract: A method for manipulating a quantum system comprises at least one mobile charge carrier with a magnetic moment. The method comprises the steps or acts of applying magnetic field to the charge carrier. The magnetic is spatially non-homogeneous. The method also comprises bringing the charge carrier into an oscillatory movement along a path. The magnetic field depends on the position of the charge carrier on said path. The oscillatory movement may be caused by electrostatic interaction with gate electrodes. Due to this approach, thus, in a magnetic moment resonance process the conventional oscillating magnetic field is replaced by an oscillating electric field which is locally transformed into a magnetic field by the Coulomb interaction that displaces the charge carrier wave function within an inhomogeneous magnetic field or in and out of a magnetic field.Type: GrantFiled: May 26, 2004Date of Patent: February 26, 2008Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Gian R. Salis
-
Patent number: 7242604Abstract: A memory element, logic element or sensor element is provided, which element comprises a switchable first magnetic component exhibiting a ferromagnetic or ferrimagnetic behaviour and comprising at least two magnetic domains with different magnetization directions and a domain wall between the magnetic domains. The element has electrodes operable to induce an electric current which at least partially flows through the domain wall with a current density high enough to cause the domain wall to reversibly propagate within the magnetic component. The first magnetic component may belong to a layered system further including a second magnetic component with a fixed magnetization and a non-magnetic spacer layer arranged between the first and second magnetic component. In such a layered system, the electrical resistance may depend on the relative orientation of the magnetization directions of the first and second magnetic component, due to the GMR or TMR effect.Type: GrantFiled: January 11, 2006Date of Patent: July 10, 2007Assignee: International Business Machines CorporationInventors: Mathias Klaeui, Rolf Allenspach, Pierre-Olivier Jubert
-
Publication number: 20060221677Abstract: A memory element, logic element or sensor element is provided, which element comprises a switchable first magnetic component exhibiting a ferromagnetic or ferrimagnetic behaviour and comprising at least two magnetic domains with different magnetisation directions and a domain wall between the magnetic domains. The element has electrodes operable to induce an electric current which at least partially flows through the domain wall with a current density high enough to cause the domain wall to reversibly propagate within the magnetic component. The first magnetic component may belong to a layered system further including a second magnetic component with a fixed magnetisation and a non-magnetic spacer layer arranged between the first and second magnetic component. In such a layered system, the electrical resistance may depend on the relative orientation of the magnetisation directions of the first and second magnetic component, due to the GMR or TMR effect.Type: ApplicationFiled: January 11, 2006Publication date: October 5, 2006Applicant: International Business Machines CorporationInventors: Mathias Klaeui, Rolf Allenspach, Pierre-Olivier Jubert
-
Publication number: 20050276149Abstract: A method for manipulating a quantum system comprises at least one mobile charge carrier with a magnetic moment. The method comprises the steps or acts of applying magnetic field to the charge carrier. The magnetic is spatially non-homogeneous. The method also comprises bringing the charge carrier into an oscillatory movement along a path. The magnetic field depends on the position of the charge carrier on said path. The oscillatory movement may be caused by electrostatic interaction with gate electrodes. Due to this approach, thus, in a magnetic moment resonance process the conventional oscillating magnetic field is replaced by an oscillating electric field which is locally transformed into a magnetic field by the Coulomb interaction that displaces the charge carrier wave function within an inhomogeneous magnetic field or in and out of a magnetic field.Type: ApplicationFiled: May 26, 2004Publication date: December 15, 2005Inventors: Rolf Allenspach, Gian Salis
-
Publication number: 20050260839Abstract: Processes, apparatus and systems for depositing a switching material that is switchable between conductivity states and where the states are persistent. The invention further relates to a microelectronic device or non-volatile resistance switching memory comprising the switching material for storing digital information. A process includes a step of depositing the switching material by a CMOS deposition technique at a temperature lower than 400° C.Type: ApplicationFiled: April 14, 2005Publication date: November 24, 2005Applicant: International Business Machines CorporationInventors: Rolf Allenspach, Johannes Bednorz, Gerhard Meijer, Chung Lam, Richard Stutz, Daniel Widmer
-
Patent number: 6960782Abstract: Described is an electronic device comprising a junction formed between a first fullerene layer having a first doping concentration and a second fullerene layer having a second doping concentration different from the first doping concentration. The first doping concentration may be zero. The first and/or the second fullerene layer may be a monolayer. The second fullerene layer may comprise an electron donor. One example of such a device is a diode wherein the first fullerene layer is connected to an anode and the second fullerene layer is connected to a cathode. Another example is a field effect transistor wherein the first fullerene layer serves as a gate region and the second fullerene layer serves as a channel region. The second fullerene layer may alternatively comprise an electron acceptor. At least one of the first and second fullerene layers may be formed from C60, or may consist of a single bucky ball.Type: GrantFiled: April 28, 2003Date of Patent: November 1, 2005Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Urs T. Duerig, Walter Riess, Reto Schlittler
-
Publication number: 20050104101Abstract: A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.Type: ApplicationFiled: November 19, 2003Publication date: May 19, 2005Applicant: International Business Machines CorporationInventors: Jonathan Sun, Rolf Allenspach, Stuart Stephen Parkin, John Slonczewski, Bruce Terris
-
Patent number: 6700720Abstract: A scheme for ultrafast magnetization reversal in an in-plane magnetized layer (3) is disclosed. For that, an external magnetic field {right arrow over (H)}ex is applied such that the magnetization {right arrow over (M)} precesses around the external magnetic field {right arrow over (H)}ex and the external magnetic field {right arrow over (H)}ex is maintained until the precession suffices to effect the magnetization reversal. The external magnetic field {right arrow over (H)}ex is applied approximately perpendicular to the magnetization {right arrow over (M)}.Type: GrantFiled: December 7, 2001Date of Patent: March 2, 2004Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Christian Horst Back, Hans-Christof Otto Siegmann
-
Publication number: 20040016922Abstract: Described is an electronic device comprising a junction formed between a first fullerene layer having a first doping concentration and a second fullerene layer having a second doping concentration different from the first doping concentration. The first doping concentration may be zero. The first and/or the second fullerene layer may be a monolayer. The second fullerene layer may comprise an electron donor. One example of such a device is a diode wherein the first fullerene layer is connected to an anode and the second fullerene layer is connected to a cathode. Another example is a field effect transistor wherein the first fullerene layer serves as a gate region and the second fullerene layer serves as a channel region. The second fullerene layer may alternatively comprise an electron acceptor. At least one of the first and second fullerene layers may be formed from C60, or may consist of a single bucky ball.Type: ApplicationFiled: April 28, 2003Publication date: January 29, 2004Inventors: Rolf Allenspach, Urs T. Duerig, Walter Riess, Reto Schlittler
-
Patent number: 6680808Abstract: The present invention relates to computer storage systems which have a tip (24) directed close or in contact to the storage medium (10) by which bit-writing and bit-reading is enforced. It is proposed to use a magnetizable storage medium (10), expose it to an artificial, external magnetic field H coupled externally to the storage medium, and—during bit writing—to concurrently apply heat very locally in bit size dimension in order to let the external magnetic field become locally larger than the (temperature-dependent) coercive field at the location (32) where heat is applied.Type: GrantFiled: March 1, 2001Date of Patent: January 20, 2004Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Gerd K. Binnig, Walter Haeberle, Peter Vettiger
-
Patent number: 6631057Abstract: The present invention concerns at least an antiferromagnetic layer, which is in direct contact with a ferromagnetic layer for inducing an exchange bias in the ferromagnetic layer. Thus, the ferromagnetic layer is pinned by the antiferromagnetic layer, also referred to as the pinning layer. The antiferromagnetic or pinning layer comprises a compound from the group of orthoferrites, which show a variety of advantages. For example, these antiferromagnets can have a Néel temperature TN ranging from at least 623 K to 740 K depending on the compounds, and they can display a weak ferromagnetic moment. Therefore, a magnetic device comprising the mentioned structure can be used properly in an environment of a high operating temperature. The compound can be described by the formula RFe1−xTMxO3with R a rare earth element or Yttrium, and TM a transition metal which can be one element of the groups IB to VIII.Type: GrantFiled: March 8, 2000Date of Patent: October 7, 2003Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Jean Fompeyrine, Eric Fullerton, Jean Pierre Locquet, Timothy Moran, Maria Seo
-
Patent number: 6621732Abstract: A ferromagnetic pinned layer (1) kept at a fixed magnetic orientation by a pinning layer (4) is separated from a ferromagnetic free layer (3) by a Mott insulator coupling layer (2). A controllable voltage source (5) is connected between the pinned layer (1) and the free layer (3). A sublayer of the coupling layer (2) whose width (d) increases with the voltage is converted to an electrically conducting and magnetically coupling metallic state. The magnetic exchange field acting on the free layer (3) which is controlled by the applied voltage via the width (d) of the electrically conducting sublayer of the coupling layer (2) can be used to switch the free layer (3) between states of parallel and antiparallel orientations with respect to the magnetic orientation of the pinned layer (1). This is used in memory cells and in a write head.Type: GrantFiled: October 5, 2001Date of Patent: September 16, 2003Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Johannes G Georg Bednorz, Ingmar Meijer
-
Patent number: 6414808Abstract: A method of generating or modifying patterns of topically specific magnetic modifications in an at least potentially ferromagnetic surface comprising the step of subjecting the surface to a controlled impact of energized subatomic particles, preferably in the form of electron radiation, directed at the surface for producing a predetermined pattern of discrete magnetized areas on the surface. The method serves to increase the density of magnetically coded information on magnetic media, such as hard disks.Type: GrantFiled: September 24, 1999Date of Patent: July 2, 2002Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Andreas Bischof, Urs T. Duerig
-
Publication number: 20020048186Abstract: A ferromagnetic pinned layer (1) kept at a fixed magnetic orientation by a pinning layer (4) is separated from a ferromagnetic free layer (3) by a Mott insulator coupling layer (2). A controllable voltage source (5) is connected between the pinned layer (1) and the free layer (3). A sublayer of the coupling layer (2) whose width (d) increases with the voltage is converted to an electrically conducting and magnetically coupling metallic state. The magnetic exchange field acting on the free layer (3) which is controlled by the applied voltage via the width (d) of the electrically conducting sublayer of the coupling layer (2) can be used to switch the free layer (3) between states of parallel and antiparallel orientations with respect to the magnetic orientation of the pinned layer (1). This is used in memory cells and in a write head.Type: ApplicationFiled: October 5, 2001Publication date: April 25, 2002Applicant: International Business Machines CorporationInventors: Rolf Allenspach, Bednorz Johnannes G, Meijer Gerhard Ingmar
-
Publication number: 20010019461Abstract: The present invention relates to computer storage systems which have a tip (24) directed close or in contact to the storage medium (10) by which bit-writing and bit-reading is enforced. It is proposed to use a magnetizable storage medium (10), expose it to an artificial, external magnetic field H coupled externally to the storage medium, and—during bit writing—to concurrently apply heat very locally in bit size dimension in order to let the external magnetic field become locally larger than the (temperature-dependent) coercive field at the location (32) where heat is applied.Type: ApplicationFiled: March 1, 2001Publication date: September 6, 2001Inventors: Rolf Allenspach, Gerd K. Binnig, Walter Haeberle, Peter Vettiger
-
Patent number: 6104189Abstract: A magnetoresistive spin valve sensor is described. Such a sensor is also known as a GMR sensor or giant magnetoresistive sensor. The layers (24, 26, 28) of the sensor are mounted on a substrate (20) having steps or terraces on one of its face. The steps or terraces on the substrate's surface cooperate with one or more of the ferromagnetic layers (24, 28) of the sensor to determine the layers' magnetic properties. Specifically, the thickness of one or more of the sensor's layers can be set above or below a critical thickness which determines whether the easy direction of uniaxial magnetization of a layer of that particular material is fixed or "pinned". If pinned, the layer has a high coercive field. Thus, the new device avoids a biasing layer to pin any of the magnetic layers. Preferably the easy axes of the first two ferromagnetic layers (24, 28) are set at 90.degree. to one another in the zero applied field condition by appropriate choice of layer thickness.Type: GrantFiled: June 10, 1998Date of Patent: August 15, 2000Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Wolfgang F. Weber
-
Patent number: 5867025Abstract: A magnetoresistive spin valve sensor is described. Such a sensor is also known as a GMR sensor or giant magnetoresistive sensor. The layers (24, 26, 28) of the sensor are mounted on a substrate (20) having steps or terraces on one of its face. The steps or terraces on the substrate's surface cooperate with one or more of the ferromagnetic layers (24, 28) of the sensor to determine the layers' magnetic properties. Specifically, the thickness of one or more of the sensor's layers can be set above or below a critical thickness which determines whether the easy direction of uniaxial magnetization of a layer of that particular material is fixed or "pinned". If pinned, the layer has a high coercive field. Thus, the new device avoids a biasing layer to pin any of the magnetic layers. Preferably the easy axes of the first two ferromagnetic layers (24, 28) are set at 90.degree. to one another in the zero applied field condition by appropriate choice of layer thickness.Type: GrantFiled: June 13, 1997Date of Patent: February 2, 1999Assignee: International Business Machines CorporationInventors: Rolf Allenspach, Wolfgang F. Weber