Spintronics
As
rapid
progress
in
the
miniaturizationof
semiconductor
electronic devices leads toward chip
features smaller than 100 nanometers
in size, engineers and physicists are
certainly faced with the alarming
presence of quantum mechanics. One such peculiarity is a
quantum property of the electron known as spin, which is closely
related to magnetism. Devices that rely on an electron's spin to
perform their functions form the foundation of Spintronics, also
known as Magnetoelectronics. Information processing technology
has thus far relied on purely charge-based devices -ranging from
the now old-fashioned vacuum tube to today's million-transistor
microchips. Those conventional electronic devices move electric
charges around, ignoring the spin that tags along for the ride on
each electron.
Spintronics is a new branch of electronics in which electron spin,
in addition to charge, is manipulated to yield a desired outcome
.All spintronic devices act according to the simple scheme: (1)
information is stored (written) into spins as a particular spin
orientation (up or down), (2) the spins, being attached to mobile
electrons, carry the information along a wire, and (3) the
information is read at a terminal. Spin orientation of conduction
electrons survives for a relatively long time (nanoseconds,
compared to tens of femto seconds during which electron
momentum decays), which makes spintronic devices particularly
attractive for memory storage and magnetic sensors applications,
and, potentially for quantum computing where electron spin
would represent a bit (called qubit) of information.
Eng. Fajir Alenizi