Spintronics
Electronics and Spintronics
Thus far, information processing technology has relied exclusively on charge-based devices ranging from the obsolete vacuum tubes to today’s million-transistor microchips. What has been neglected in these devices is that the electrons carrying the charge are equipped with an additional property, known as the spin. The spin is closely related to magnetism and in a magnetic material, the electrons are spin-polarized, that is, most spins prefer to point in the same direction.
It has been known for several decades that the resistance in a magnetic material depends on the direction of magnetization (and therefore the spin). In the late 1980s, it was shown that the resistance change became gigantic in hybrid magnetic/non-magnetic multi-layered metallic structures and the effect was named Giant Magneto Resistance (GMR). This discovery laid the foundation of a field that today is referred to as spintronics (short for spin-electronics). The GMR effect was applied to read heads for magnetic hard drives in the mid 1990s and allowed a vast increase in storage density.
The technology foundation of Spintronix was developed at the Royal Institute of Technology (KTH) in Stockholm. The most fundamental is the manufacturing of a semiconductor (ZnO:Mn) that has ferromagnetic properties at room temperature. This will greatly enhance the possibilities for future memory and computational devices based on spintronics.
Spintronics
Spintronics, or spin electronics, refers to the role played by electron spin in solid state physics, and possible devices that specifically exploit spin properties instead of or in addition to charge degrees of freedom. For example, spin relaxation and spin transport in metals and semiconductors are of fundamental research interest not only for being basic solid state physics issues, but also for the already demonstrated potential these phenomena have in electronic technology. The electrons are not transported in spintronics which dramatically increases performance and capacity.
The area of Spintronics in where one successfully can control the electron’s spin degree of freedom as well as its charge to store, process and transmit information has encountered major roadblocks which we will briefly survey. Scientifically, this new area of research is fascinating as one of the potential applications of spin based electronics has been in the rapidly booming field of quantum computing.
While there are clear advantages for introducing semiconductors in novel spintronic applications. In addition to the near-term studies of various spin transistors and spin transport properties of semiconductors, a long-term and ambitious subfield of spintronics is the application of electron and nuclear spins to quantum information processing and quantum computation. It has long been pointed out that quantum mechanics may provide great advantages over classical physics in physical computation. However, the real boom started after the advent of Shor's factorization algorithm and quantum error correction schemes. Among the many quantum computer hardware that were proposed are the ones based on electron and nuclear spins.
The market push for using and developing spin devices has increased drastically. E.g. Intel has decided to implement wireless communication in all their new developments of computer chip, This means an increased pull from the market to increase memory capacity with a lower battery consumption. M-RAM can be the solution for this. This type of memory is based on spintronic materials. The memory cell does not require any power until the cell is read or changed. The spintronic technology gives the possibility to dramatically increase capacity, read and write speed with very low power consumption. This development alos opens up for a more optimized and effective processor design.
http://en.wikipedia.org/wiki/Spintronics |
