Andrew Tully Kent

US Patent:

7170778, Jan 30, 2007

Filed:

Oct 13, 2005

Appl. No.:

11/250791

Inventors:

Andrew Kent - New York NY, US
Enrique Gonzalez Garcia - New York NY, US
Barbaros Ozyilmaz - Brooklyn NY, US

Assignee:

New York University - New York NY

International Classification:

G11C 11/14

US Classification:

365171, 365158, 365173, 3652255, 365 97, 365 66

Abstract:

The present invention generally relates to the field of magnetic devices for memory cells that can serve as non-volatile memory. More specifically, the present invention describes a high speed and low power method by which a spin polarized electrical current can be used to control and switch the magnetization direction of a magnetic region in such a device. The magnetic device comprises a pinned magnetic layer with a fixed magnetization direction, a free magnetic layer with a free magnetization direction, and a read-out magnetic layer with a fixed magnetization direction. The pinned magnetic layer and the free magnetic layer are separated by a non-magnetic layer, and the free magnetic layer and the read-out magnetic layer are separated by another non-magnetic layer. The magnetization directions of the pinned and free layers generally do not point along the same axis. The non-magnetic layers minimize the magnetic interaction between the magnetic layers.

US Patent:

7307876, Dec 11, 2007

Filed:

Aug 1, 2006

Appl. No.:

11/498303

Inventors:

Andrew Kent - New York NY, US
Daniel Stein - New York NY, US

Assignee:

New York University - New York NY

International Classification:

G11C 11/14

US Classification:

365171, 365158, 365173, 3652257, 365 97, 365 66

Abstract:

A high speed and low power method to control and switch the magnetization direction and/or helicity of a magnetic region in a magnetic device for memory cells using spin polarized electrical current. The magnetic device comprises a reference magnetic layer with a fixed magnetic helicity and/or magnetization direction and a free magnetic layer with a changeable magnetic helicity. The fixed magnetic layer and the free magnetic layer are preferably separated by a non-magnetic layer, and the reference layer includes an easy axis perpendicular to the reference layer. A current can be applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to thereby read out the information stored in the device.

US Patent:

7573737, Aug 11, 2009

Filed:

Oct 31, 2007

Appl. No.:

11/932745

Inventors:

Andrew Kent - New York NY, US
Barbaros Ozyilmaz - Brooklyn NY, US
Enrique Gonzalez Garcia - Orlando FL, US

Assignee:

New York University - New York NY

International Classification:

G11C 11/15

US Classification:

365173, 365171, 365158, 365 66

Abstract:

A high speed and low power method to control and switch the magnetization direction and/or helicity of a magnetic region in a magnetic device for memory cells using spin polarized electrical current. The magnetic device comprises a reference magnetic layer with a fixed magnetic helicity and/or magnetization direction and a free magnetic layer with a changeable magnetic helicity. The fixed magnetic layer and the free magnetic layer are preferably separated by a non-magnetic layer, and the reference layer includes an easy axis perpendicular to the reference layer. A current can be applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to thereby read out the information stored in the device.

US Patent:

7911832, Mar 22, 2011

Filed:

Jun 24, 2009

Appl. No.:

12/490588

Inventors:

Andrew Kent - New York NY, US
Daniel Stein - New York NY, US
Jean-Marc Beaujour - Elmhurst NY, US

Assignee:

New York University - New York NY

International Classification:

G11C 11/14

US Classification:

365171, 365173, 365170, 365158

Abstract:

A high speed and low power method to control and switch the magnetization direction and/or helicity of a magnetic region in a magnetic device for memory cells using spin polarized electrical current. The magnetic device comprises a reference magnetic layer with a fixed magnetic helicity and/or magnetization direction and a free magnetic layer with a changeable magnetic helicity and/or magnetization direction. The fixed magnetic layer and the free magnetic layer are preferably separated by a non-magnetic layer. The fixed and free magnetic layers may have magnetization directions at a substantially non-zero angle relative to the layer normal. A current can be applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to read out the information stored in the device.

US Patent:

7986544, Jul 26, 2011

Filed:

Nov 5, 2007

Appl. No.:

11/935392

Inventors:

Andrew Kent - New York NY, US
Barbaros Özyilmaz - Singapore, SG

Assignee:

New York University - New York NY

International Classification:

G11C 11/00

US Classification:

365148, 365158, 365171

Abstract:

The present invention generally relates to magnetic devices used in memory and information processing applications, such as giant magneto-resistance (GMR) devices and tunneling magneto-resistance devices. More specifically, the present invention is directed to a single ferromagnetic layer device in which an electrical current is used to control and change magnetic configurations as well as induce high frequency magnetization dynamics. The magnetic layer includes full spin-polarized magnetic material, which may also have non-uniform magnetization. The non-uniform magnetization is achieved by varying the shape or roughness of the magnetic material. The present invention may be used in memory cells, as well as high frequency electronics, such as compact microwave sources, detectors, mixers and phase shifters.

US Patent:

8363465, Jan 29, 2013

Filed:

Mar 4, 2011

Appl. No.:

13/041104

Inventors:

Andrew Kent - New York NY, US
Daniel Stein - New York NY, US
Jean-Marc Beaujour - Elmhurst NY, US

Assignee:

New York University - New York NY

International Classification:

G11C 11/14

US Classification:

365171, 365 97, 365131, 365170, 365173, 365158

Abstract:

A high speed and low power method to control and switch the magnetization direction and/or helicity of a magnetic region in a magnetic device for memory cells using spin polarized electrical current. The mapetic device comprises a reference magnetic layer with a fixed magnetic helicity and/or magnetization direction and a free magnetic layer with a changeable magnetic helicity and/or magnetization direction. The fixed magnetic layer and the free magnetic layer are preferably separated by a non-magnetic layer. The fixed and free magnetic layers may have magnetization directions at a substantially nonzero angle relative to the layer normal. A current can be applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to read out the information stored in the device.

US Patent:

20050041462, Feb 24, 2005

Filed:

Aug 19, 2003

Appl. No.:

10/643762

Inventors:

Andrew Kent - New York NY, US
Enrique Gonzalez Garcia - New York NY, US
Barbaros Ozyilmaz - Brooklyn NY, US

International Classification:

G11C011/00

US Classification:

365158000

Abstract:

The present invention generally relates to the field of magnetic devices for memory cells that can serve as non-volatile memory. More specifically, the present invention describes a high speed and low power method by which a spin polarized electrical current can be used to control and switch the magnetization direction of a magnetic region in such a device. The magnetic device comprises a pinned magnetic layer with a fixed magnetization direction, a free magnetic layer with a free magnetization direction, and a read-out magnetic layer with a fixed magnetization direction. The pinned magnetic layer and the free magnetic layer are separated by a non-magnetic layer, and the free magnetic layer and the read-out magnetic layer are separated by another non-magnetic layer. The magnetization directions of the pinned and free layers generally do not point along the same axis. The non-magnetic layers minimize the magnetic interaction between the magnetic layers. A current is applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to thereby read out the information stored in the device.

US Patent:

20120294078, Nov 22, 2012

Filed:

Nov 16, 2011

Appl. No.:

13/298190

Inventors:

Andrew Kent - New York NY, US
Daniel Bedau - New York NY, US
Huanlong Liu - New York NY, US

International Classification:

G11C 11/14

US Classification:

365171

Abstract:

Orthogonal spin-transfer magnetic random access memory (OST-MRAM) uses a spin-polarizing layer magnetized perpendicularly to the free layer to achieve large spin-transfer torques and ultra-fast energy efficient switching. OST-MRAM devices that incorporate a perpendicularly magnetized spin-polarizing layer and a magnetic tunnel junction, which consists of an in-plane magnetized free layer and synthetic antiferromagnetic reference layer, exhibit improved performance over prior art devices. The switching is bipolar, occurring for positive and negative polarity pulses, consistent with a precessional reversal mechanism, and requires an energy less than 450 fJ and may be reliably observed at room temperature with 0.7 V amplitude pulses of 500 ps duration.