The giant magnetoresistance effect (GMR) is a quantum mechanical effect observed in thin film structures composed of alternating ferromagnetic and nonmagnetic metal layers.

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Two ferromagnetic layers are separated by a non-magnetic spacer layer. The ferromagnetic layers will couple with anti-parallel orientation when the spacer layer is sufficiently thin. An external magnetic field can break the coupling resulting in a significantly lower electrical resistance. This so called GMR-effect can be used to build a sensor for magnetic fields and can be found in read heads of magnetic mass storage devices.

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It results from subtle electron-spin effects in ultra-thin 'multilayers' of magnetic materials, which cause huge changes in their electrical resistance when a magnetic field is applied. GMR is 200 times stronger than ordinary magnetoresistance. [See Spintronics and Giant Magneto Resistance] GMR enables sensing of significantly smaller magnetic fields, which in turn allows hard disk storage capacity to increase by a factor of 20.

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(Gmr). It results from subtle electron-spin effects in ultra-thin 'multilayers' of magnetic materials, which cause huge changes in their electrical resistance when a magnetic field is applied. Gmr is 200 times stronger than ordinary magnetoresistance. [see spintronics and giant magneto resistance] gmr enables sensing of significantly smaller magnetic fields, which in turn allows hard disk storage capacity to increase by a factor of 20

Source

It results from subtle electron-spin effects in ultra-thin 'multilayers' of magnetic materials, which cause huge changes in their electrical resistance when a magnetic field is applied. GMR is 200 times stronger than ordinary magnetoresistance. [See Spintronics and Giant Magneto Resistance] GMR enables sensing of significantly smaller magnetic fields, which in turn allows hard disk storage capacity to increase by a factor of 20.

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