Goodbye, hard! What will replace hard drives

© Flickr / mattandkimЖесткий diskGoodbye, hard! What will replace hard drives© Flickr / mattandkim

The first device for recording information appeared in the middle of the last century. Since then they have significantly decreased in size and increased in density. But the volume of digital information (images, texts, graphics, calculations) is steadily increasing, and scientists continue to improve methods, materials and schemes for data storage.

Today the most popular storage medium for personal computers is the hard disk. Its advantages include low price, good (relative to other available media) the recording density and almost infinite possibility of overwriting of data, and significant disadvantages — low speed read/write data, the risk of failure of mechanical parts, the consumption of large quantities of electricity and noise when working.

Describe the structure of the hard disk as simply as possible: is the structure of the cells (physical storage units), each of which can have a status of «0» or «1» depending on the magnetization. Writing and reading of information is performed using a magnetic head, «riding» over the cell array. The most common cause of hard drive failure becomes a failure of the system to implement the movement of the head.

Modern alternative hard disk — SSD (solid-state drive), solid state drive. It is less bulky and faster, but has weak durability, and the price until six to seven times higher. The SSD is the transistor. In fact, the readability of the cell information depends on accumulated charge. Erasing of information is carried out by the withdrawal of the charge using high negative voltage.

The data media still fully satisfy the needs of home users of personal computers. However, in the military, scientific and industrial applications require the highest possible recording density. This can be achieved by reducing the cell size and the distance between them.

In the last two decades, active research of molecules able to be magnetized when applying the field and keep this state when it is disconnected. Potentially, such a molecule is capable of storing one bit of information that may lead to the emergence of a storage device with a huge density of data. However, while molecular magnets only work at very low temperatures (minus 258 degrees C and below), which greatly hinders their practical application.

Researchers from IBM and the Institute of fundamental Sciences in Seoul, has demonstrated a method of reading and recording information on individual atoms of rare earth metal holmium, able to retain the magnetization for a long time. The scheme of the device consisted of a system of two atoms of holmium and iron (the latter was needed to read the magnetic state) on a substrate made of magnesium oxide. In the experiment, atoms are recorded and considered them sequentially four different States, including a combination of logical zeros and ones. System for five hours kept this magnetization.

The distance between the cells in the media is limited by their stability. Too close located the magnetic cells may lead to their interaction and erasing data. An alternative to the magnetic material can become skyrmions — quasiparticles, which are formed some substances of spins (magnetic moments) of electrons under the action of a magnetic field. For education skyrmion need a few atoms of matter, but such quasi-particles are stable and do not succumb to the influence of skyrmions-neighbors. The size of the combination of atoms needed to create skorpiona equal to several nanometers. Properties skorpionov can be managed, therefore, to carry out the rewriting of information.

While described alternative methods of recording information are under development. Their full set of properties (and advantages and disadvantages) will be known only after the creation and testing of prototypes.