Introduction To The World Of Spin
#1

Introduction To The World Of Spin
( A Concept Based Innovative Technology Of Future Through Electronics )

Nikhil.G.S, Rony Renjith.
III Department of Electronics and Communication
Maria College Of Engineering and Technology

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Abstract
As spintronics goes nano, new phenomena are predicted resulting from the interplay between spin
dependent transport and single electron physics. The long term goal of manipulating spins one by
one would open a promising path to quantum computing. Towards this end, there is an ever-growing
effort to connect spin tanks (i.e. ferromagnetic leads) to smaller and smaller objects in order to study
spintronics in reduced dimensions. Spin is not completely replacing charge but giving new definitions
and better stability. This paper discusses the basic spintronics theory, its areas and developments,
current researches, spintronic devices and its applications, future concepts, limitations and
advantages. Discussions on nanolevel spintronic study is also involved. Brief future directions in the
emerging field of nanospintronics towards quantum dots, carbon nanotubes and single molecule
magnets.is also included.

Introduction
Spintronics, spin-electronics, or magnetoelectronic
is currently the focus of an intense research effort .
In spintronics, we manipulate the spin degree of
freedom of an electron as opposed to, or in addition
to, manipulating the charge as we do in conventional
electronic s. Spin is a quantum two-level system;
states are quantum superpositions of "up" and
"down", the two basis states in which the physical
system can be found. Spin reflects the quantum
nature of an electron so that the remarkable property
of quantum parallelism, which is so useful in
quantum computation, for instance, can be achieved
with spin states. Although spintronics is not
expected to replace traditional electronics, it will
likely play a complementary role to electronics, in
particular in the domain of quantum information.
Research in spintronics has been proceeding at a
rapid pace, both experimentally and theoretically.
New effects have been predicted, and then detected
in the lab. As new experimental data become
available, new interpretations are required. Although
the study of the motion of charges can serve as a
guide, the methods need to be adapted to the
specifics of the spin degree of freedom

Defnition
Spintronics(aneologism meaning "spin
transportelectronics"), also known as
magnetoelectronics, is an emerging technology that
exploits the intrinsic spin of electrons and its associated magnetic moment, in addition to its
fundamental electronic charge, in solid-state
devices. Spin S is an angular momentum with the
physical dimension of action, i.e., energy
-time.Like charge, spin is an intrinsic property of
an electron. Its magnitude is fixed once and for
all,but its
orientation is not. This is unlike the orbital angular
momentum L, whose classical counterpart is
familiar from merry -go-round physics, and which
depends on the position r and the linear momentum
P through the relation L = r x P and can therefore
take on many values depending on the spatial
distribution of the electron.The electron spin is
expressed as
S= (h/2)σ
where h, Planck's fundamental quantum of action,
provides the dimension, the factor ½ determines the
magnitude of the spin and , σ the Pauli spin
operator, determines its properties

History
The research field of Spintronics emerged from
experiments on spin-dependent electron transport
phenomena in solid-state devices done in the 1980s,
including the observation of spin -polarized electron
injection from aferromagnetic metal to a normal
metal by Er.Jiveshwar Sharma (Jove) and Johnson
and Silsbee (1985), and the discovery of giant
magnetoresistance independently by Albert Fert et
al. and Peter Grünberg et al. (1988).The origins can
be traced back further to the ferro
magnet/superconductor tunnelling experiments
pioneered by Meservey and Tedrow, and initial
experiments on magnetic tunnel junctions by Julliere
in the 1970s.The useof semiconductors for
spintronics can be traced back at least as far as the
theoretical proposal of a spin field-effect-transistor
by Datta and Das in1990

Theory
Electrons are spin-1/2 fermions and therefore
constitute a two-state system with spin "up" and spin
"down". To make a spintronic device, the primary
requirements are to have a system that can generate a
current of spin polarized electrons comprising more of
one spin species—up or down—than the other (called a
spin injector), and a separate system that is sensitive to
the spin polarization of the electrons (spin detector).
Manipulation of the electron spin during transport
between injector and detector (especially in
semiconductors) via spin precession can be
accomplished using real external magnetic fields or
effective fields caused by spin-orbit interaction. Spin
polarization in non-magnetic materials can be achieved
either through the Zeeman effect in large magnetic
fields and low temperatures, or by non-equilibrium
methods. In the latter case, the non-equilibrium
polarization will decay over a timescale called the "spin
lifetime". Spin lifetimes of conduction electrons in
metals are relatively short (typically less than 1
nanosecond) but in semiconductors the lifetimes can be
very long (microseconds at low temperatures),
especially when the electrons are isolated in local
trapping potentials (for instance, at impurities, where
lifetimes can be milliseconds).

References
S. M. Metev and V. P. Veiko, Laser Assisted
Microtechnology, 2nd ed., R. M. Osgood, Jr., Ed.
Berlin, Germany: Springer-Verlag, 1998.
J. Breckling, Ed., The Analysis of Directional Time
Series: Applications to Wind Speed and Direction,
ser. Lecture Notes in Statistics. Berlin, Germany:
Springer, 1989, vol. 61.
S. Zhang, C. Zhu, J. K. O. Sin, and P. K. T. Mok, “A
novel ultrathin elevated channel low-temperature
poly-Si TFT,” IEEE Electron Device Lett., vol. 20,
pp. 569–571, Nov. 1999.
M. Wegmuller, J. P. von der Weid, P. Oberson, and
N. Gisin, “High resolution fiber distributed
measurements with coherent OFDR,” in Proc.
ECOC’00, 2000, paper 11.3.4, p. 109.
R. E. Sorace, V. S. Reinhardt, and S. A. Vaughn,
“High-speed digital-to-RF converter,” U.S. Patent 5
668 842, Sept. 16, 1997.
(2002) The IEEE website. [Online]. Available:
http://ieee
M. Shell. (2002) IEEEtran homepage on CTAN.
[Online]. Available: http://ctantex-
archive/macros/latex/contrib/supported/IEEEtran/
FLEXChip Signal Processor (MC68175/D),
Motorola, 1996.
“PDCA12-70 data sheet,” Opto Speed SA,
Mezzovico, Switzerland.
A. Karnik, “Performance of TCP congestion control
with rate feedback: TCP/ABR and rate adaptive
TCP/IP,” M. Eng. thesis, Indian Institute of Science,
Bangalore, India, Jan. 1999.
J. Padhye, V. Firoiu, and D. Towsley, “A stochastic
model of TCP Reno congestion avoidance and
control,” Univ. of Massachusetts, Amherst, MA,
CMPSCI Tech. Rep. 99-02, 1999.
Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specification, IEEE Std.
802.11, 1997

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