Recording data using heat could lead to faster, more efficient magnetic recording devices

A recent study has shown that heat can be used to magnetically store data on tiny magnetic grains

For the past several decades, it has been assumed that in order to store data on a magnetic medium, a magnetic field must be applied. Recently, however, an international team of scientists discovered that heat can be used instead of a magnetic field. Not only is this method reportedly more energy efficient, but it also theoretically allows for ten times the storage capacity and 300 times the performance of current hard drive technology.
Traditionally, hard drives have worked by using a magnetic field to invert the polarity of magnetic domains within the drive platter - the stronger that field, the faster bits of data can be recorded. In the new study, however, it was discovered that those same inversions could be attained by applying ultra-
short pulses of heat (in the form of laser light) to a field of densely-packed nanometer-sized magnetic grains. The rate at which this could be done was equivalent to 200 Gigabytes per second.

Initially two grains have different magnetic orientation (black and white respectively), but after the application of a single pulse, the magnetic direction of both islands changes - further pulses repeat the process, switching the magnetic state back and forth

"Instead of using a magnetic field to record information on a magnetic medium, we harnessed much stronger internal forces and recorded information using only heat," said physicist Thomas Ostler from the University of York, which led the project. "This revolutionary method allows the recording of Terabytes (thousands of Gigabytes) of information per second, hundreds of times faster than present hard drive technology. As there is no need for a magnetic field, there is also less energy consumption."
Not only could the new technique save energy, but it might also be a way of utilizing the waste heat generated by computers.
A paper on the research was recently published in the journal Nature Communications.
Source: University of York