Magnetic recording assisted by spin torque oscillator with a radio frequency current bias
US8582240B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2012 |
| Grant date | Nov 12, 2013 |
| Priority date | — |
| Expiry date | Aug 29, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0024
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A design is disclosed for a microwave assisted magnetic recording device wherein direct current and rf current are simultaneously injected from a bias tee into a spin transfer oscillator (STO) between a main pole and write shield to improve the assist process. The STO oscillation layer (OL) has a large angle magnetization oscillation frequency that is locked to a magnetic medium bit resonance frequency f0 when the rf current has a frequency f=f0 and a threshold current density is applied. Alternatively, the OL magnetization oscillation frequency may be adjusted closer to f0 to improve the assist process. A third advantage is lowering the threshold current density when both direct current and rf current are injected into the STO during a write process. The main pole is grounded when direct current and rf current are injected into a write shield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.