Magnetic reading head and magnetic recording apparatus
US8072713B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2008 |
| Grant date | Dec 6, 2011 |
| Priority date | — |
| Expiry date | Oct 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To provide a magnetic reading head that features high resolution and low noise, and that can support a hard disk with terabit-level surface recording density. A current is caused to flow from a pinned layer with its magnetization direction fixed by an antiferro magnetic material, to a non-magnetic thin wire having a portion affected by an external magnetic field and a portion not affected by the external magnetic field, so that spin polarized electrons are accumulated in the non-magnetic thin wire. A distance between voltage terminals of a voltmeter is set to less than the spin diffusion length of the non-magnetic thin wire. A change in the external magnetic field modulates some of the accumulated spin polarized electron, but does not others. Accordingly, an electrical potential difference depending on the external magnetic field is generated between the both end surfaces of the non-magnetic thin wire, and measured with the voltmeter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.