SPINTRONICS-FUTURE OF ELECTRONICS.

ABSTRACT

Spintronics also called as magnetoelectroincs deals with the use of spin of electrons rather than the charge of electrons to store, process and data signal. There are many announcements to make drive of 1 TB on single sided 3.5" diameter disc using spintronics. There are various techniques involved that use semiconductor as well as metal for exploiting spin. MRAM is the most acclaimed product of spintronics, it uses magnetic tunnel concept in working and is non-volatile and more robust. One of the major advantages of spintronics over electronics is that magnets tend to stay magnetized, which is sparking in the industry an interest for replacing computer' semiconductor based components with magnetic ones, starting with the RAM.

WHAT IS 'SPINTRONICS'?

Spintronics or spin electronics refers to the study of the role played by electron(and more generally nuclear) spin in solid state physics and possible devices that specifically exploit spin properties instead of or in addition to the charge degree of the freedom. By exploiting this spin property, the basis of computer processing and storage technologies has been revolutionized. The word 'spintronics' itself is a blend of electronics with spin, which is the angular or rotational momentum of a subatomic particle that creates its own tiny magnetic fields. The ability to exploit spin in semiconductors promises new logic devices with enhanced functionality, high speed and reduced power consumption.

PRINCIPLE INVOLVED

Spintronics is based on the spin of the electron rather than its charge. Every electron exists in one of the two states, namely, spin-up and spin-down, with spins either positive half or negative half. Spin is the root cause of magnetism and is a kind of intrinsic angular momentum that a particle can not gain or lose. The two possible spin states naturally represent '0' and '1' in logical operations, so it i possible to make a sandwitch of gold atoms between two thin films of magnetic material that ll act as a filter or a valve permitting only the electrons in one of the two states to pass. The filter can be changed from one state to another using a brief and tiny burst of current. Spin is the characteristics that makes the electron a tiny magnet, compete with north and south poles. The orientation of the tiny magnet's north-south axis depends on the particle's axes of spin. In the atoms of an ordinary material, some of these spin axes point up(with respect to say, an ambient magnetic field) and an equal number points 'down'. The particle's spin is associated with a magnetic moment, which may be thought of as the handle that lets a magnetic field torque the electon's axis of spin. Thus in ordinary material, the up moments cancel the down ones, so no surplus moment piles up.

For that a ferromagnetic like iron, nickel or cobalt is needed. These have tiny regions called 'domains' in which an excess of electrons have spins with axes pointing either up or down-atleast, until heat destroys their magnetism, above the metal's Curie temperature. The many domains in the direction of the field, so they point in the same direction. The result is a permanent magnet.

WORKING

When a pool of spin-polarized electron is put in a magnetic field, precession occurs. The frequency and the direction of rotation depend on the strength of the magnetic material in which precession is taking place. Thus if a voltage pushes an electron out of gallium arsenide into zinc selenide the electrons precession characteristics changes. However, if a higher voltage pushes the electron sharp enough into zinc selenide, the precession characteristics do not change but remain those of gallium arenide for a while. n-type materials rely on electrons, while p-types on poles to carry current. Because the materials are of two different charge carrier types, an electric field is formed around their junction. This field is strong enough to pull a poll of spin coherent electrons from GaAs immediately into ZnSe where coherence persists for hundreds of nanoseconds. Now, n-type and p-type materials can be built and the spin can get through the interface between them just fine. The spin can be moved from one kind of semiconductor into another without the need of any extenal field. Basically all spintronics devices act according to the simple scheme: the information is stored(written) into spin as a particular spin orientations(up or down). The spins, being attached to mobile electrons, carry the information along a wire and the information is read at a terminal.

Bustling satti bazaar and its staff(mera nazariya)

In the bustling satti market, u can hear the sound of "sabjiwallah`s",shouting loudly and with aggression ofcourse "Sabzzzi le lo-o-o !!!" and the respective name of their vegetables, well i m mentioning the one of the most hampy-shampy place of Raipur.Quite strange it is but i love the place ,sometimes i just rush to this place, to admire the chaos there.They use mind blowing language like they call carry bag-parri, and "laali laali pataal lelo mai 2 rupya ma" is the most distinguished one i remember. From my childhood i buy sabji from market,i dont prefer those street sellers at the doorstep with their cycle containing bundles of "jholas", and all their products are upbeaten.My mom send me to market with a "jhola" and a lot of change each for the specified counter.Then i view it as most responsible job, that time i dont know how but there is always a hole in my pant's pocket , so often i have to return home crying to be safe from my mom's anger. well that was in raigarh moving our engine back to satti bazaar, it has every sort of fruits and vegetables.There is a bunch of fruit-sellers at the entrance,i always wonder why they keep sweet tamarind no ones buy that, atleast i havent seen yet. As u move inside u can find the rich sabjiwallahs ,with a stall as big as any levi's store,they too contain all unseasonal sabji. the real market reside at the heart of it. they all sit in their zig zag row.they have the fresh stock of and u sould say that they r the most busiest person over there.the best part comes now bargaining. my mom says "Bargain with them fiercly".actaully bargaining was an act of great individuality for her, as well as a social intercourse. so u can see aunties shouting loudly for 1 or 2 rupya, as if the whole world will crash down if they leave that. in summer the market is full of yellow shades of mango, i love spending summer morning there.The stall of bhaaji waali's are awesome, full of fresh and green spinach,laal bhaji,and there are dozens of bhaaji i even dont remember there name.this para of appreciation is for all thse sabji walli's and walla's out there and also to satti bazaar which is no less than BSE. kudos to you....................

Google making fun of NASA......

HEY guys u would be shocked to hear that , google is organizing a competition of sending a land rover robot to moon , and whats the hit is only private firms are allowed to participate , even the website makes fun of government mission of space. and the 1st prize is 30 MILLION $. THE MISSION HAS TO BE CMPLTD BEFORE 2012........................

FOR MORE DETAILS LOG ON TO    www.googlelunarxprize.org/  .