Patent attributes
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.
