Spintronics “A Spin to

Remember”Submitted To :Mr. S.P AGARWAL(HOD Deptt. Of EX)

Submitted by :

Ravisha Shringi

12EMHEX020

contents WHAT IS SPINTRONICS WHY SPINTRONICS BASIC PRINCIPLE ADVANTAGES GIANT MAGNETO RESISTANCE(GMR) TUNNEL MAGNETORESISTANCE ELECTRONICS V/S SPINTRONICS APPLICATIONS

Conventional electronic devices ignore the spin property and rely strictly on the transport of the electrical charge of electrons.

Adding the spin degree of freedom provides new effects, new capabilities and new functionalities

INTRODUCTION

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.

WHY SPINTRONICS? Moore’s law -states that the number of transistors on a silicon chip will roughly double every eighteen months. By 2008, it is projected that the

width of the electrodes in a microprocessor will be 45nm across

As electronic devices become smaller, quantum properties of the wavelike nature of electrons are no longer negligible.

Spintronic devices offer the possibility of enhanced functionality, higher speed, and reduced power consumption.

Basic principle In Spintronics , information is carried by

orientation of spin rather than charge. Spin can assume one of the two states

relative to the magnetic field, called spin up or spin down.

These states, spin up or spin down, can be used to represent ‘1’ and ‘0’ in binary logic.

In certain spintronic materials, spin orientation can be used as spintronic memory as these orientation do not change when system is switched off.

ADVANTAGES OF SPINTRONICS

Low power consumption. Less heat dissipation. Spintronic memory is non-volatile. Takes up lesser space on chip, thus more compact. Spin manipulation is faster , so greater read & write speed. Spintronics does not require unique and specialized semiconductors. Common metals such as Fe, Al, Ag , etc. can be used.

GAINT MAGNETORESISTANCE (GMR) The basic GMR device consists of a layer of

non -magnetic metal between two magnetic layers.

A current consisting of spin-up and spin-down electrons is passed through the layers.

Those oriented in the same direction as the electron spins in a magnetic layer pass through quite easily while those oriented in the opposite direction are scattered.

Tunnel magnetoresistance Magnetic tunnel junction has two

magnetic layers separated by an insulating metal-oxide layer.

Is similar to a GMR spin valve except that a very thin insulator layer is sandwiched between magnetic layers instead of metal layer.

The difference in resistance between the spin-aligned and nonaligned cases is much greater than for GMR device infact 1000 times higher than the standard spin valve.

Electronics v/s spintronics

One of the main advantage of spintronics over electronics is the magnets tend to stay magnetize which is sparking in the industry an interest for replacing semiconductor based components with magnetic ones, starting with the RAM.

With an all-magnetic RAM, it is now possible to have a computer that retains all the information put into it. Most importantly, there will be no “boot-up” waiting period when power is turned on.

Another promising feature of spintronics is that it doesn’t require the use of unique and specialized semiconductor, there by allowing it to work with common metals like Cu, Al, Ag.

Spintronics will use less power than conventional electronics, because the energy needed to change spin is a minute fraction of what is needed to push charge around.

applications The Magnetic version of RAM used

in computer is nonvolatile.

Other advantages of include small size, lower cost, faster speed and less power consumption, robust in extreme condition such as high temperature, high level radiation and interference.

Conclusion Spin property of electrons are yet to

mastered. Researcher and scientist are taking

keen interest. Span of last two decade major

milestones. It holds vast opportunities for

physics , material & device engineering & technology.

Any queries??

Thank you!!!