spintronics ppt

Submitted To: Presented By :

Mr. Devendra Pratap Singh SHISHU PAL

Ms. Kanika Jindal 1213331191

Ms. Gitanjali Anand ECE.(3rd Year)

A

SEMINAR PRESENTATION

on

Contents

Introduction

Evolution

Motivation

Technology description

Circuit Diagram

Advantages/disadvantages

Future Aspects

Real time Applications

References

INTRODUCTION

An electron has a charge and spin

(spin) + (charge)

Spintronics is abbreviation of “spin transport electronics" & itsalso known as magnetoelectronics, is an emerging technology thatexploits both the intrinsic spin of the electron and its associatedmagnetic moment, in addition to its fundamental electronic charge,in solid-state devices.

-e-e

Intrinsic angular momentum is spin

Two arbitrary orientations,up (+1/2) and down (-1/2)

Directional and coherent motion of electron spin circulates a spin

current, which will carry or transport information and control

quantum spin in an spintronic device.

EVOLUTION

Failure of Moore’s Law :

Moore’s Law states that ” the number of transistors on a siliconchip will roughly double every eighteen months.”

But now the transistors & other components have reached nanoscaledimensions and further reducing size lead to Quantum effect.

1988 France, GMR discovery is accepted as birth of spintronics

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

MOTIVATION

Conventional Electronics Charge

• Based on number of charges and their energy

• Performance limited in speed and dissipation

Spintronics Spin

• Based on the direction of spin and spin coupling

• Capable of much higher speed at very low power

TECHNOLOGY

Spin can assume one of the two states relative to the magnetic

field, called spin up or spin down.

The states, spin up or spin down, can be used to represent

‘1’ and ‘0’ in binary logic

The simplest method of generating a spin- polarised current in a

metal is to pass the current through a ferromagnetic material. The

most common application of this effect is a giant

magnetoresistance (GMR) device

Giant Magneto Resistance (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 layers.

Those oriented in the same direction as the electron spins in a

magnetic layers pass through quite easily while those oriented in

the opposite direction are scattered.

SPIN VALVES If the orientation of one of the magnetic layers be changed then

the device will act as a filter, or ‘spin valve’, letting through more

electrons when the spin orientations in the two layers are the same

and fewer when orientations are oppositely aligned.

The electrical resistance of the device can therefore be changed

dramatically.

Magnetic Random Access Memory

The elements are mostly tunnel junctions formed from two

ferromagnetic plates

Each of which can hold a magnetic field, separated by thin

insulating layer

ELECTRONICS v/s SPINTRONICS

Electronics

Based on properties of

charge of the electron

Classical Mechanism

Materials: conductors and

semiconductors

Based on the number of

charges

Speed is limited and power

dissipation is high

Spintronics

Based on intrinsic property

spin of electron

Quantum Mechanism

Materials: ferromagnetic

materials

Two basic spin states; spin-up

and spin-down

Based on direction of spin and

spin high coupling, high speed.

ADVANTAGE OF SPINTRONICS

Low power consumption.

Less heat dissipation.

Spintronics memory is non-volatile.

Takes up lesser space on chip, thus more compact.

The MRAM has all the properties of DRAM ,SRAM and ROM .

Spintronics does not require unique and specialized

semiconductors.

Common metals such as Fe, Al, Ag , etc. can be used.

FUTURE ASPECTS

Hard drives up to 1.2 petabytes

Magnetic RAM chips

Spin FET using quantum tunneling

Integrating spin-devices with current microelectronics and

computing

And research is still going on…

REALTIME APPLICATION

iPod nano

Laptop hard drives

Cell phone

4GB Compact Flash card

Spin- based Transistor

Commercial products.. .

REFERENCES

1. Electronic measurement and control of spin transport

2. en.wikipedia.org/wiki/Spintronics

3. http://www.slideshare.net

4. http://seminarproject.com

5. www.physik.uni-regensburg.de/.../Spintronics

Thanks for your attention…!!!

Any Queries ??