[LINK] Fwd: vip-l: Article: Fujitsu Hard Drives: Toward 1TB per Square Inch

[Jan Whitaker]

>This article is taken from the Beta News home page at 
>www.betanews.com.  -Steve.
>
>Fujitsu Hard Drives: Toward 1TB per Square Inch
>By Scott M. Fulton, III,
>BetaNews
>November 29, 2006, 7:08 PM
>
>A laser capable of being focused to a spot on a rotating disk just 
>80 nanometers
>across, is what Fujitsu needed to be able to beat competitors 
>Toshiba and Seagate,
>in the race toward terabit areal densities. Yesterday, Fujitsu 
>announced they'd achieved
>that goal.
>
>While Toshiba and Seagate have been in competition with one another 
>to drive up the
>areal density of hard drives using new perpendicular recording 
>technology, the scientists
>at Fujitsu -- whose own consumer drives have had to play catch-up 
>recently in the
>quality department -- have been planning to leap-frog their 
>competitors in one fell
>swoop. There's a physical maximum, they found, to how densely data 
>can be packed
>even with perpendicular mechanisms.
>
>Their objective is to overcome that physical barrier by means of a 
>curious physical
>trick involving at least three devices a hard drive has never had to 
>use thus far:
>a very small space heater, a virtual refrigerator just as small, and 
>an optical reading
>mechanism.
>
>You read correctly: an optical
>  element, not a magnetic one, but not for reading the data. It's to 
> locate the spot
>on the rotating disk where the heating element will work its 
>alchemy. Up to now,
>Fujitsu has had two of the three elements in its back pocket. 
>Yesterday, it announced
>the third: an optical element that will help future hard drives 
>achieve areal densities
>greater than the 1 terabyte (TB) per square inch theoretical maximum.
>
>The blame for the maximum limit on magnetic recording, according to 
>Fujitsu scientists
>Koji Matsumoto, Akihiro Inomata, and Shin-ya Hasegawa, has to do 
>with the size of
>ferromagnetic (iron) grains. You can theoretically make them as 
>small as you want,
>but if you make them any smaller than they already are, they won't 
>retain their magnetic
>charge over a sustained period of time. The act of writing data 
>literally heats these
>grains up, which helps them retain data; but over time, as they very 
>gradually cool,
>the likelihood that they'll lose their data increases as they fall 
>victim to what
>Fujitsu scientists call thermal fluctuation.
>
>As a result, you can't miniaturize the magnetic grain enough to 
>enable read/write
>heads, using the current technology, to store data up to an areal 
>density of 1 TB/sq2.
>Fujitsu's proposed solution is extraordinary, involving changing the 
>physical properties
>of the storage media temporarily, just at the point of the write 
>operation, using specifically focused heat. At room temperature, it 
>takes a relatively sizeable magnetic charge (
>coercivity) to erase the state of stored data on a disk so it can be 
>changed. But as the temperature
>in the vicinity rises, the amount of charge required decreases. If 
>you heat a material
>up just enough, to what's called the Curie temperature, it loses its 
>magnetism altogether.
>For the Fujitsu process to work, a heating element needs to bring 
>the write spot
>on the disk up to as close to the Curie temperature as possible, 
>though just below.
>As you might have guessed, what Fujitsu needs is a laser, but one 
>which is integrated
>directly into the magnetic write head of the drive. Its spot size 
>needs to be no
>greater than 50 nanometers (nm).
>
>This way, the laser can heat up the precise spot on the drive where 
>data can be stored
>using a minimal charge. When the spot is rapidly cooled, it then 
>holds its charge
>for a theoretically long period of time.
>
>Up to now, it's all been theory; what Fujitsu needed was what others 
>would consider
>a miracle in near-field optics. Yesterday, the company's labs 
>announced they'd achieved
>something at least very close to that miracle: While scientists were 
>hoping for 50
>nm x 50 nm with 2% optical efficiency, they achieved 80 nm x 60 nm, 
>though with 17%
>optical efficiency.
>
>It might just work. If it does, the terabit barrier will be broken, 
>and the mechanism
>that takes manufacturers past that barrier will have a Fujitsu 
>patent stamped all
>over it. If Seagate and Toshiba were wondering what's been holding 
>Fujitsu up for
>so long, they just got their answer.

Jan Whitaker
JLWhitaker Associates, Melbourne Victoria
jwhit at janwhitaker.com
business: http://www.janwhitaker.com
personal: http://www.janwhitaker.com/personal/
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'Seed planting is often the most important step. Without the seed, 
there is no plant.' - JW, April 2005
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