9. What is Spintronics? Spintronics is a blend of electronics with spin. It refers to the study of the role played by the electron spin in solid state physics and possible devices that specifically exploits spin properties of electrons instead of it’s charge. It promises new logic devices which enhances functionality, high speed and reduced power consumption.
10. Principle Spintronics is based on the spin of electrons rather than its charge. Every electron exist in one of the two states- spin-up and spin-down, with spins either positive half or negative half. In other words, electrons can rotate either clock wise or anti-clockwise around its own axis with constant frequency. The two possible spin states represent ‘0’ and ‘1’ in logical operations.
11. Principle Spin is a characteristic that makes an electron a tiny magnet with north and south poles. The orientation of north-south axis depends on the particle’s axis of spin. In ordinary materials, the up magnetic moments cancel the down magnetic moment so no surplus moment piles up. Ferro-magnetic materials like iron, cobalt and nickel is needed for designing of spin electronic devices.
12. Principle These have tiny regions called domains in which an excess of electrons have spins with axis pointing either up or down. The domains are randomly scattered and evenly divided between majority-up and majority-down. But, an externally applied magnetic field will line up the domains in the direction of the field. This results in a permanent magnet.
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14. Principle When a pool of spin-polarized electrons is put in a magnetic field, precession occurs. The frequency and direction of rotation depends on the strength of magnetic field and characteristics of the material. Thus, if a voltage pushes an electron out of gallium arsenide into zinc selenide, the electron precession characteristics change. However, if a higher voltage pushes the electron sharply into zinc selenide, the electron precession characteristics don’t change.
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17. Finding the novel ways of both generation and utilization of spin polarized current. The later one is a effective method.
18. Working All spintronic devices acts according to the simple scheme: The information is stored (written) into spins as a particular spin orientation (up or down). The spins, being attached to mobile electrons, carry information along a wire and the information is read at a terminal. Spin orientation of conduction electrons survives for relatively long time (nanoseconds, compared to tens of femtoseconds during which electron moment decays) which makes spintronic device useful for memory storage and magnetic sensor applications.
19. Working These are used for quantum computing where electron spin will represent a bit (called ‘qubit’) of information. When electron spins are alligned, this creates a large scale net magnetic moment. The basic GMR device is a 3 layer sandwich of magnetic metal (such as cobalt) with a non-magnetic metal filling (such as silver). A current passes through the layers consisting of spin up and spin down electrons.
20. The electrons oriented in the same direction as the electron spin in the magnetic layer pass through quite easily while those oriented in the opposite direction are scattered. If orientation of one of the magnetic layers is changed by the presence of a magnetic field, the device will act as a filter or a spin valve letting through more electrons when spin orientation in the two layers are the same and fewer electrons when spin orientation are oppositely alligned.
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27. Fast and accurate position and motion sensing of mechanical components in precision engineering and robotics.
32. Conclusion With lack of dissipation, spintronics may be the best mechanism for creating ever-smaller devices. The potential market is enormous, In maybe a 10-year timeframe, spintronics will be on par with electronics. That's why there's a huge race going on around the world In exploring Spintronics.