Hitachi discovers way to create HDD with density of 1Tb per square inch

The Hitachi Cambridge Laboratory in the UK, in collaboration with several universities in Europe, has discovered "Coulomb blockade anistropic magneto-resistance (CBAMR)," a magneto-resistance (MR) effect that shows more than 100 times larger electric resistance due to magnetism compared to ordinary MR effects. The company claims this is "an achievement that leads us to the realization of a playback head for HDDs with a surface recording density of more than 1 terabit per 1 inch square." The experiment was conducted at -269°, but the research group found out from simulation that this effect may last even at room temperature.

The MR effect, which represents a phenomenon that electric resistance strengthens by magnetism, is observed at less than 10% using the obsolete MR head, less than 100% using the GMR head, which is the most used today, and about 400% in fundamental tests using the TMR head, which is increasingly used these days. The newly found CBAMR effect sharply boosts these MR effects by 100 times at a breath. In experiments, the group created a single-electron transistor consisting of 5-nm thin Ga-Mn-As ferromagnetic semiconductor film, and confirmed more than 100 times stronger electric resistance using the transistor.