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Now if only we had computers fast enough to process all that data.
Researchers at Sun Yat-Sen University in China have demonstrated a way to record on ferromagnetic films using laser-assisted ultrafast magnetization reversal dynamics. The development will allow for practical use of new technology for recording more than 6,000 terabits (6 petabits) of data on a single 5-inch disc, using ultra-high-density magneto-optical storage devices.
The new ultrafast recording technique uses “time-resolved polar Kerr spectroscopy†combined with an alternating magnetic field strong enough to re-initialize the magnetization state of gadolinium-iron-cobalt (GdFeCo) thin films. The researchers showed that the magnetization reversal could occur on a sub-nanosecond time scale, which implies that next-generation magneto-optical storage devices can not only realize higher recording densities but also ultrafast data writing of up to a gigahertz — at least thirty times faster than that of present hard disks in computers.
Laser-assisted magnetic recording was demonstrated on a sub-picosecond time scale under a saturated external magnetic field. “We found that the rate of magnetization reversal is proportional to the external magnetic field,†says Tianshu Lai, “and the genuine thermo-magnetic recording should happen within several tens to hundreds of picoseconds when we apply a smaller magnetic field than the coercivity of the recording films.â€
Reference: “Field-dependent ultrafast dynamics and mechanism of magnetization reversal across ferrimagnetic compensation points in GdFeCo amorphous alloy films†by Tianshu Lai, Zhifeng Chen, Ruixin Gao, Zixin Wang, Chudong Xu and Daxin C. (Zhongshan (Sun Yat-Sen) University) appears in the Journal of Applied Physics.
More info:American Institute of Physics news