Currently, we have several methods of storing and transmitting data. The most common method followed is storing data on a magnetic hard disk in the form of bits. Here minute magnetic domains form a North and a South pole pair, with the direction of the magnetization of the poles defining whether the stored bit is a digital 1 or a 0. Writing the data means physically switching the magnetization of the relevant bit, one at a time.
Switching or changing the magnetization of each bit requires the application of an external magnetic field, which forces the alignment of the poles to change to either up or down for representing a digital 1 or a 0 respectively.
However, it is also possible to use light to flip the magnetization. Two things are required here, one, very short laser pulses of femtosecond wavelength, and the second, synthetic ferrimagnets that respond to these laser bursts. Using laser and ferrimagnetic material makes data storage far faster compared to what can be achieved by magnetization alone. Ferrimagnets are materials that work with spintronics with the application of a femtosecond laser pulse, and that makes the whole process extremely fast and energy-efficient.
As such, light offers the most energy-efficient method of sending and receiving information. However, storing light is not an easy task. That is the reason data centers all over the world prefer to use magnetic storage methods such as tapes and disks, even though these methods consume a lot of energy to operate. This hybrid technique of storing information using lasers and electric current, developed by researchers at TU Eindhoven at the Institute of Photonic Integration, was presented in the journal Nature Communications. The new method combines the advantages of the high speed of light and ease of magnetic storage. They are using ultra-short pulses of light to write the information directly on a magnetic medium, the result is highly energy efficient and the speed of operation matches the speed of light.
Scientists using the above method of data storage with lasers, have another trick up their sleeve. They combined this optical switching with race-track memory. Here, the data is stored inside a magnetic wire and transported using an electric current. Now, as soon as the bit is stored at one end of the wire using the laser burst, it can be efficiently transported along by the current, freeing up space and thereby allowing the laser to write the next bit.
This efficient on-the-fly operation with the help of lasers and current using magnetic race-tracks does not require any intermediate electronic step. In fact, the physical analogy the scientists offer for this method is of a person jumping back and forth between two high-speed trains moving alongside each other, instead of using a station to change over from one train to the other. The laser and current method, therefore, represents faster speed and higher efficiency.
Obviously, the wires are actually micro-wires. The scientists who designed the system plan to reduce the wires to nano-scale in the future to enable them to be integrated inside chips. They are also working on reading information using optical methods.