RELATIVISTIC CHIPS: THE SPINTRONICS THEORY
@ No microprocessor of the world can challenge BRAIN, the ultimate biochemical machine.
@ Mooreâ„¢s law still holds good.
@ Heat and energy are the two main constraints of the present IC technology.
@ Relativity may be the Answer.
@ Even the worldâ„¢s fastest computers are not very faster, but the electrons in them do.
RELATIVISTIC CHIPS:THE CONCEPT
@ Einstein proposed the THEORY OF RELATIVITY.
@ THOERY OF RELATIVITY suggests a new design for microchips that relies on the spin of electrons.
@ These so-called relativistic effects are all minuscule, however, unless the object accelerates to a significant fraction of c, which is about 300 million meters per second.
@ Though the high end chips are not as fast as light but the electrons inside them do.
@ SPINTRONICS, short for spin electronics, is the study of electron spin in materials in order to better understand its behavior, with the hope of developing an entirely new generation of microelectronic devices.
@ An electron is just like such a spinning sphere of charge.
@ The electron has a quantum property, called spin, that makes it behave almost as if it were a magnet twirling about the axis connecting its north and south poles. Electrons (spheres) can have spins oriented in different directions.
@ A magnetic field causes an electron to swivel like the needle of a compass to line up with the field (left). But the spin axis also precesses like a wobbling top (right).
When the magnetic field is removed, the electron stops precessing and locks the orientation of its spin
@ SPIN FET was proposed in 1990 by Supriyo Datta and Biswajit A. Das, at Purdue University, in West Lafayette.
@ They proposed a current modulator device based on the electric field modification of spin precession in a narrow gap semiconductor. In this device, the spin-polarized electrons would be injected with the use of a ferromagnetic electrode that forms an ohmic contact with the semiconductor and would be detected with a second ferromagnetic electrode (spin analyzer) contact.
MRAM (Magnetic RAM)
MRAM stands for Magnetic Random Access Memory.
@ It places the magnetic domains on the surface of a silicon chip and places a magneto-resistive sensor beneath every one of them. Just like a hard disk, the information stored in the magnetic domains is non-volatile. It is not lost when the power goes off.
The two main concept that govern MRAM technology are:
Ãƒ Giant Magnetoresistance (GMR) effect
Ãƒ The Tunneling Magneto-Resistive (TMR) effect
@ A Transpinnor is a bridge of four electrically connected GMR(giant magnetoresistive) films whose resistance is controlled by the magnetic field from the current in one or more input striplines electrically isolated from the GMR films.
@ Transpinnors can be used as selection-matrix elements for magnetic memories, for logic elements of all kinds (e.g., AND, OR, XOR, NAND, NOT), for amplifiers, differential amplifiers.