Miniaturization of the chips to the smallest possible in size has being one of the biggest unachieved challenges. But with the research going on in spintronics, the day of overcoming the unthinkable barrier is not too far
Miniaturization has always been a part of rapidly developing electronic industry. But there is a limit to the number of transistor or other electronic component that can be cramped on a single chip. Besides this, small electronic devices are plagued by a big problem of energy loss or dissipation, as signals pass from one transistor to the next transistor. So the only solution to overcome this problem is to find some method that takes both the problem into account.
Apart from miniaturization another problem with current devices is that their working is based on use of electronic charges. This working has several disadvantages; power failure being one of them. In case of a power cut, information stored by electronic charges is lost. Hence, before a computer is turned off, all the work is saved on the hard disk.
`Spintronics` or Spin electronics, is one of the solutions to overcome this problem. Spintronics is based on the spin of the electron rather than its charge. Every electron exists in one of two states, namely, spin-up and spin-down, with spins either positive half or negative half. Thus by exploiting the `spin` of the electron rather than its charge, physicists are trying to create a remarkable new generation of `spintronic` devices which will be smaller, more versatile and more robust than those currently making up silicon chips and circuit elements. These Spintronic devices will work in following manner:
(1) Information will be stored (written) into spins as a particular spin orientation (up or down)
(2) The spins, being attached to mobile electrons, will carry the information along a wire
(3) The information will be read at a terminal.
Also, replacing the semiconductor components in a computer with magnetic components would provide more options and feasibility, which was not possible with electronic devices.
Avoiding energy loss or dissipation
So far, only superconductors were known to carry current without any dissipation, which was possible only at extremely low temperatures, typically -150 degree Celsius. And due this characteristic they could not be used in commercial devices. But by modifying electron`s spin property with a sensitive spin detector, dissipationless spin current could be made to flow even at room temperature. With lack of dissipation, spintronics may be the best mechanism for creating ever-smaller devices.
The various advantages of Spintronics are as follows:
- Spintronics does not require unique and specialised semiconductors, therefore it can be implemented or worked with common metals, such as Copper, Aluminium and Silver.
- Spintronics devices would consume less power compared to conventional electronics, because the energy needed to change spin is a easy compared to energy needed to push charge around.
- Since Spins don`t change when power is turned off, the memory remains non-volatile.
If an attempt were made to make magnetic RAM capable of retaining important data, it would be very difficult task to achieve. The primary reason being interference of fields with nearest element.
Suppose individual memory elements are addressed by flipping their spins up or down to yield the zeros and ones of binary computer logic. In that case, the common strategy of running current pulses through wires to induce magnetic fields to rotate the elements is flawed. This may happen because the fringe fields that are generated may interfere with neighboring elements.
Spintronics still remains to be far away from being the best friend and source of electronic industry. But in order to convert it into reality, many major manufacturers have already started investigating magnetic RAM technology, and they are keeping their eyes on magnetic CPUs for the future. As the development in spintronics is bound to bring a new era of semiconductor spintronics that could potentially transform the microelectronics industry. But more importantly, with the magnetic storage industry currently accounting for billions
|Posted : 3/16/2006|