Three-terminal spin-torque oscillator (STO)
US8320080B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2011 |
| Grant date | Nov 27, 2012 |
| Priority date | — |
| Expiry date | May 31, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/1936
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spin-torque oscillator (STO) has a single free ferromagnetic layer that forms part of both a giant magnetoresistance (GMR) structure with a nonmagnetic conductive spacer layer and a tunneling magnetoresistance (TMR) structure with a tunnel barrier layer. The STO has three electrical terminals that connect to electrical circuitry that provides a spin-torque excitation current through the conductive spacer layer and a lesser sense current through the tunnel barrier layer. When the STO is used as a magnetic field sensor, the excitation current causes the magnetization of the free layer to oscillate at a fixed base frequency in the absence of an external magnetic field. A detector coupled to the sense current detects shifts in the free layer magnetization oscillation frequency from the base frequency in response to external magnetic fields.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.