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overwhelmedblueearthAI and Robotics

Dec 1, 2013 (3 years and 8 months ago)

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OUTLINE

INTRODUCTION TO QUANTUM DOTS

NECESSITY OF QUANTUM DOTS: LIMITATIONS OF CURRENT CMOS
BASED TECHNOLOGY

HOW ARE QUANTUM DOTS GENERATED?

WHAT IS QUANTUM DOT CELLULAR AUTOMATA (QCA)?

LOGICAL IMPLEMENTATION OF QCA IN QUANTUM COMPUTATION

APPLICATION OF QCA

CONCLUSION





INTRODUCTION TO QUANTUM DOTS


IN ANY MATERIAL, THERE EXISTS A QUASI
-
PARTICLE NAMED ‘EXCITON’

AN

EXICITON

IS

DEFINED

AS

THE

BOUND

STATE

OF

AN

ELECTRON

AND

HOLE

WHICH

ARE

ATTRACTED

TO

EACH

OTHER

BY

COULOMB’S

ELECTROSTATIC

FORCE







-------------

WIKIPEDIA


A

QUANTUM

DOT

IS

A

SEMICONDUCTOR

WHOSE

EXCITONS

ARE

CONFINED

IN

ALL

THREE

SPATIAL

DIMENSIONS
.

AS

A

RESULT,

THEY

HAVE

PROPERTIES

THAT

ARE

BETWEEN

THOSE

OF

BULK

SEMICONDUCTORS

AND

THOSE

OF

DISCRETE

MOLECULES
.

QUANTUM

DOTS,

THUS,

ARE

SEMICONDUCTOR

NANOCRYSTALS

OF

RANGE

2
-
10

nm

(
10



50

ATOMS)

IN

DIAMETER

AND

SINCE

THEY

ARE

SO

SMALL,

THEY

ARE

CONSIDERED

DIMENSIONLESS
.


SIMULATED QUANTUM DOT GENERATION

SOURCE:
-

http://www.onlineinvestingai.com/blog/2009/02/04/whats
-
the
-
spin
-
on
-
quantum
-
dots/



National Institute of Nanotechnology at the University of Alberta

UNDERSTANDING QUANTUM DOTS

IN

ITS

TRUE

FORM,

QUANTUM

DOTS

CAN

BE

UNDERSTOOD

TO

BE

SMALL

DEVICES

CONTAINING

TINY

DROPLET

OF

FREE

ELECTRONS
.

THUS,

ANY

QUANTUM

DOT

CONSISTS

OF

ANYTHING

FROM

A

SINGLE

ELECTRON

TO

A

CLUSTER

OF

A

NUMBER

OF

ELECTRONS
.

IT

CAN

BE

UNDERSTOOD

TO

BE

AN

ARTIFICALLY

CREATED

ATOM

WITH

3
D

SPATIAL

CONFINEMENT

OF

ELECTRONS

WITH

THE

ONLY

DIFFERENCE

BEING

THAT

THERE

CAN

BE

SIGNIFICANT

CHANGE

IN

THE

PROPERTIES

OF

THE

QUANTUM

DOT

EVEN

IF

A

SINGLE

ELECTRON

WERE

TO

LEAVE

THE

STRUCTURE
.

ANIMATION






-----------

WIKIPEDIA

AN EXAMPLE OF QUANTUM DOTS

COURTESY
:
-

The

size

of

the

quantum

dots

can

be

tuned

to

produce

several

different

colors

(Image
:

Nature)

COURTESY
:
-

The

structural

aspects

and

light
-
emitting

properties

of

quantum

dots

P
.

O’Brien,

S
.

S
.

Cummins,

D
.

Darcy,

A
.

Dearden,

O
.

Masala,

N
.

L
.

Pickett,

S
.

Ryley

and

A
.

J
.

Sutherland

(
2003
),

“Quantum

dot
-
labelled

polymer

beads

by

suspension

polymerization
.


Chem
.

Commun
.

2532
-
2533

and

www
.
nanoco
.
biz
.


NECESSITY OF QUANTUM DOTS: LIMITATIONS OF
CURRENT CMOS BASED TECHNOLOGY


1.
CMOS

TRANSISTORS

CAN

NOT

BE

SCALED

BEYOND

A

PARTICULAR

SIZE

ANY

FURTHER

2.
CMOS

INTERCONNECTS

HAVE

NOT

GROWN

TO

WORK

AS

FAST

AS

THE

DEVICES

THEMSELVES

3.

POWER

CONSUMPTION

DUE

TO

LEAKAGE

CURRENT

IS

SIGNIFICANT

IN

THE

CMOS

TECHNOLOGY

AND

HAS

NO

100
%

SOLUTION

TO

IT

AT

THIS

POINT

IN

TIME



ADVANTAGES OF QUANTUM DOT TECHNOLOGY



1.
OPTIMISTIC

ASSUMPTIONS

INDICATE

THAT

THE

TECHNOLOGY

HAS

THE

POTENTIAL

TO

BREAK

THE

TERAHERTZ

BARRIER

(THEORETICALLY

PROVEN)

2.

POWER

CONSUMPTION

IS

SIGNIFICANTLY

LOW

AS

COMPARED

TO

THE

CMOS

TECHNOLOGY

3.

THE

INTERCONNECTS

DESIGNED

WITH

QCA

WOULD

BE

FASTER

AND

WOULD

WORK

ALMOST

UP

TO

THE

SPEED

OF

THE

PROCESSING

DEVICE

WHICH

WOULD

DRASTICALLY

ENHANCE

THE

SYSTEM

PERFORMANCE

Courtesy
:
-

Quantum
-
dot

Cellular

Automata

(QCA)

-

Logic

Gates

By

John

C
.

Bean

University

of

Virginia,

Charlottesville,

VA

HOW ARE QUANTUM DOTS GENERATED?

ESSENTIALLY

QUANTUM

DOTS

ARE

OF

3

TYPES

DEPENDING

ON

THE

PHYSICS

OF

HOW

THE

ELECTRON

CONFINEMENT

OCCURS

IN

THE

SEMICONDUCTOR

MATERIAL


1.
PLANAR

QUANTUM

DOTS

2.

VERTICAL

QUANTUM

DOTS

3.

SELF
-
ASSEMBLED

QUANTUM

DOTS


HOW ARE QUANTUM DOTS GENERATED?

QUANTUM

DOTS

ARE

GENERATED

BY

THE

PHENOMENON

KNOWN

AS

ELECTRON

TRAPPING

OR

CONFINEMENT

IN

AN

ENERGY

WELL

OF

DISCRETE

MAGNITUDE
.

THIS

WOULD

GENERATE

‘EXCITONS’

IN

AN

ATOM

THERE

ARE

DIFFERENT

WAYS

OF

CONFINING

THE

EXCITONS

AND

HENCE

THERE

ARE

DIFFERENT

WAYS

TO

GENERATE

THE

QUANTUM

DOTS
.

COLLOIDAL

QUANTUM

DOTS

IRRADIATED

WITH

A

UV

LIGHT
.

DIFFERENT

SIZED

QUANTUM

DOTS

EMIT

DIFFERENT

COLOR

LIGHT

DUE

TO

QUANTUM

CONFINEMENT
.

Courtesy:
-

WIKIPEDIA


QUANTUM DOTS

HOW ARE QUANTUM DOTS GENERATED?


COLLOIDAL

SEMICONDUCTOR

NANOCRYSTALS

IRRADIATED

WITH

ULTRAVIOLET

LIGHT
.

QUANTUM

CONFINEMENT

CAUSES

THE

BAND

GAP

ENERGY

TO

VARY

WITH

THE

NANOCRYSTAL'S

SIZE
.

EACH

VIAL

CONTAINS

A

MONODISPERSE

SAMPLE

OF

NANOCRYSTALS

DISPERSED

IN

A

LIQUID

SOLVENT

(FIGURE

IN

THE

PREVIOUS

SLIDE)




FOLLOWING

ARE

THE

MOST

COMMON

WAYS

OF

PRODUCING

THE

QUANTUM

DOTS

1
.

COLLOIDAL

SYNTHESIS

:

-

INVOLVES

BINARY

ALLOYS

SUCH

AS

CADMIUM






SELENIDE,

CADMIUM

SULFIDE,

INDIUM

ARSENIDE,





AND

INDIUM

PHOSPHIDE
.

ALTHOUGH,

DOTS

MAY

ALSO

BE





MADE

FROM

TERNARY

ALLOYS

SUCH

AS

CADMIUM





SELENIDE

SULFIDE
.



Courtesy:
-

AMAZING RUST

http://www.amazingrust.c
om/experiments/current_
projects/Misc.html

HOW ARE QUANTUM DOTS GENERATED?

2.
FABRICATION
:
-

QUANTUM

DOTS

DEFINED

BY

LITHOGRAPHICALLY

PATTERNED

GATE

ELECTRODES,

OR

BY

ETCHING

ON

TWO
-
DIMENSIONAL

ELECTRON

GASES

IN

SEMICONDUCTOR

HETEROSTRUCTURES

CAN

HAVE

LATERAL

DIMENSIONS

EXCEEDING

100

NM



COURTESY
:
-

QUANTUM

DOTS

BY

ULTRAVIOLET

AND

X
-
RAY


LITHOGRAPHY

BY

MASSIMO

F

BERTINO
1
,
7

HOW ARE QUANTUM DOTS GENERATED?

COURTESY :
-

YOUTUBE VIDEO POSTED BY

www.nanophys.ethz.ch

HOW ARE QUANTUM DOTS GENERATED?

3
.

OTHER

FABRICATION

TECHNIQUES

INCLUDE

VIRAL

ASSEMBLY



(BIOLOGICALLY

PRODUCED

USING

VIRUS

DNA),

ELECTROCHEMICAL



ASSEMBLY,

BULK

MANUFACTURE

(USES

A

PROCESS

CALLED

“HIGH



TEMPERATURE

DUAL

INJECTION”

WHICH

IS

IMPRACTICAL

FOR



MOST

COMMERCIAL

APPLICATIONS

THAT

REQUIRE

LARGE



QUANTITIES

OF

QUANTUM

DOTS)

&

CADMIUM

FREE

QDs

(FREE



FROM

CdSe

SINCE

CADMIUM

IS

A

HEAVY

METAL

AND

USES

RARE



EARTH

METALS)



-------------

WIKIPEDIA

WHAT IS QUANTUM DOT CELLULAR AUTOMATA
(
QCA
) ?
-

INTRODUCTION

COURTESY :
-

YOUTUBE VIDEO POSTED BY

UNIVERSITY OF ALBERTA, CA



http://www.phys.ualberta.ca/~wolkow/news.php

WHAT IS QUANTUM DOT CELLULAR AUTOMATA
(
QCA
) ?


QUANTUM CELL DEFINED

COURTESY:
-

WIKIPEDIA (QUANTUM DOT CELLULAR AUTOMATON)

1
)

SHOWS

A

SIMPLIFIED

DIAGRAM

OF

A

QUANTUM
-
DOT

CELL
.

IF

THE

CELL

IS

CHARGED

WITH

TWO

ELECTRONS,

EACH

FREE

TO

TUNNEL

TO

ANY

SITE

IN

THE

CELL,

THESE

ELECTRONS

WILL

TRY

TO

OCCUPY

THE

FURTHEST

POSSIBLE

SITE

WITH

RESPECT

TO

EACH

OTHER

DUE

TO

MUTUALELECTROSTATIC

REPULSION
.

THEREFORE,

TWO

DISTINGUISHABLE

CELL

STATES

EXIST
.

2
)

SHOWS

THE

TWO

POSSIBLE

MINIMUM

ENERGY

STATES

OF

A

QUANTUM
-
DOT

CELL
.

THE

STATE

OF

A

QCA

REPRESENTS

ITS

POLARIZATION,

DENOTED

AS

P
.

ALTHOUGH

ARBITRARY

IN

MEANING,

USING

CELL

POLARIZATION

P

=

-
1

TO

REPRESENT

LOGIC


0


AND

P

=

+
1

TO

REPRESENT

LOGIC


1


HAS

BECOME

STANDARD

PRACTICE
.

3
)

A

WIRE

OF

QD

CELLS
.

WHAT IS QUANTUM DOT CELLULAR AUTOMATA
(
QCA
) ?


LOGIC DESIGN

COURTESY:
-

WIKIPEDIA (QUANTUM DOT CELLULAR AUTOMATON)


ASSUMING

INPUTS

A

AND

B

EXIST

IN

A

“BINARY

0


STATE

AND

INPUT

C

EXISTS

IN

A

“BINARY

1


STATE,

THE

OUTPUT

WILL

EXIST

IN

A

“BINARY

0


STATE

AS

THE

CONJUNCT

ELECTRICAL

FIELD

EFFECT

OF

INPUTS

A

AND

B

IS

GREATER

THAN

THE

ONE

OF

INPUT

C
.

IN

OTHER

WORDS,

THE

MAJORITY

GATE

DRIVES

THE

OUTPUT

CELL’S

STATE

TO

BE

EQUAL

TO

THAT

OF

THE

MAJORITY

OF

THE

INPUTS
.

NOW,

IF

THE

POLARIZATION

OF

INPUT

C

WERE

TO

BE

FIXED

TO

SAY,

BINARY

0
,

THE

ONLY

WAY

THE

OUTPUT’S

STATE

BECOMES

BINARY

1
,

IS

IF

INPUT

A

AND

B

ARE

ALSO

1
.

OTHERWISE,

THE

OUTPUT

CELL

WILL

EXHIBIT

A

BINARY

0

STATE
.

WHAT IS QUANTUM DOT CELLULAR AUTOMATA
(
QCA
) ?


LOGIC DESIGN

COURTESY:
-

WIKIPEDIA (QUANTUM DOT CELLULAR AUTOMATON)

THE

OUTPUT

CELL

SERIES

HAS

TO

BE

AT

45
0


FROM

THE

TWO

LOGICALLY

LIKE

INPUTS

TO

REALIZE

A

‘NOT’

OR

INVERTER

LOGIC

CELL

STATE

TRANSITION

FOR

LOGIC

DEFINITION


QCA

CELLS

CAN

ONLY

BE

FOUND

IN

TWO

STATES

(LOGIC


0


AND


1
’)





THE

SITUATIONAL

CHANGE

IN

THE

STATE

OF

THE

CELL

UNDERGOING

TRANSITION

IS

RELATIONAL

IN

NATURE

AND

HIGHLY

DEPENDS

ON

THE

STATE

OF

ITS

ADJACENT

NEIGHBORS




THE

MOST

IMPORTANT

ROLE

TO

GENERATE

THE

LOGIC

USING

QCA

IS

TO

DEFINE

METHOD

TO

CONTROL

DATA

FLOW

WHICH

IS

INTURN

NECESSARY

TO

DEFINE

THE

DIRECTION

IN

WHICH

STATE

TRANSITION

OCCURS

IN

QCA

CELLS


CELL

STATE

TRANSITION

FOR

LOGIC

DEFINITION

COURTESY:
-

WIKIPEDIA (QUANTUM DOT CELLULAR AUTOMATON)

THE

QCA

CLOCK,

ITS

STAGES

AND

ITS

EFFECTS

ON

A

CELL’S

ENERGY

BARRIERS

A

TYPICAL

QCA

DESIGN

REQUIRES

FOUR

CLOCKS,

EACH

OF

WHICH

IS

CYCLICALLY

90

DEGREES

OUT

OF

PHASE

WITH

THE

PRIOR

CLOCK

ADDER DESIGN IN QCA

-

CARRY FLOW ADDERS


IN

THE

QCA

TECHNOLOGY,

THE

PROPAGATION

DELAY

AND

COMPLEXITY

INCREASES

WITH

THE

INCREASE

IN

THE

NUMBER

OF

CELLS

APPLIED

TO

RESOLVE

A

LOGIC



THE

IDEA

IS

TO

USE

AS

FEWER

CELLS

AS

POSSIBLE

TO

REALIZE

THE

GIVEN

LOGIC

AND

AVOIDING

THE

ADDITION

OF

ADDITIONAL

PROPAGATION

DELAY

AND

COMPLEXITY
.

EQUATIONS

FOR

SUM

AND

CARRY

FOR

CARRY

FLOW

ADDER

ARE

S
i

= a
i
b
i
c
i

+ a’
i
b’
i
c
I
+ a’
i

b
i

c’
i

+ a’
i
b
i

c
i


c
i+1

= a
i
b
i

+ b
i
c
i

+a
i
c
i


ADDER DESIGN IN QCA

-

CARRY FLOW ADDERS

FULL

ADDER

FOR

THE

CARRY

FLOW

ADDER
.

(A)

SCHEMATIC
.

(B)

LAYOUT
.

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

ADDER DESIGN IN QCA

-

CARRY FLOW ADDERS

SIMULATION

RESULTS

FOR

8
-
BIT

CFA
.


The

first

meaningful

output

appears

in

the

third

clock

period

after

2
(
2
/
4
)

clock

delays
.

First

and

last

input/output

pairs

are

highlighted
.

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

ADDER DESIGN IN QCA

-

CARRY FLOW ADDERS

FULL

ADDER

FOR

THE

CARRY

FLOW

ADDER
.

(A)

SCHEMATIC
.

(B)

LAYOUT
.

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

ADDER DESIGN IN QCA

-

CARRY LOOK
-
AHEAD ADDERS



IN

A

SIMILAR

FASHION,

WE

CAN

DESIGN

A

CARRY

LOOKAHEAD

ADDER

WHICH

BASICALLY

ONLY

ADDS

THE

CARRY


ROUGLY

TWICE

AS

BIG

AS

THE

CARRY

FLOW

ADDER

IN

TERMS

OF

WIDTH

AND

LENGTH

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

COMPARISON OF CLA AND CFA FOR VARIOUS
OPERAND SIZES

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

MULTIPLICATION DESIGN USING QCA

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

SIMULATION RESULT OF MULTIPLIER QCA

COURTESY

:

-

ADDER

AND

MULTIPLIER

DESIGN

IN

QUANTUM
-
DOT

CELLULAR

AUTOMATA

HEUMPIL

CHO,

MEMBER,

IEEE,

AND

EARL

E
.

SWARTZLANDER,

JR
.
,

FELLOW,

IEEE

APPLICATIONS OF QUANTUM DOTS & QCA

1.
IN

QUANTUM

COMPUTATION

PROCESSING

TECHNOLOGY

IN

ORDER

TO

OBTAIN

HIGHER

BANDWIDTH

AND

OPERATING

FREQUENCIES

AND

FASTER

INTERCONNECTS

AND

LESSER

POWER

CONSUMPTION


2.
FOR

DISPLAY

TECHNOLOGY


3.
FOR

LASER

TECHNOLOGY

IN

PHOTONICS



CONCLUSION



QUANTUM

CELLULAR

AUTOMATA

IS

CURRENTLY

VIEWED

AS

THE

MOST

SUITABLE

SUCCESSOR

TO

THE

ILLUSTRIOUS

CMOS

VLSI

SYSTEM

PREVALENT

TODAY

DUE

TO

ITS

ADVANTAGES

MENTIONED
.




QUANTUM

CELLULAR

AUTOMATA

TECHNOLOGY

WOULD

BE

USED

IN

THE

FUTURE

FOR

DEVELOPING

A

HIGH

SPEED

PROCESSORS

AND

ASICs

THAT

WOULD

BE

USED

FOR

BOTH

GENERAL

PURPOSE

AND

TASK
-
SPECIFIC

COMPUTING

REQUIREMENTS





QCA

HAS

EMERGED

TO

BE

THE

PROBLEM

SOLVER

IN

THE

TIMES

WHEN

THE

WORLD

IS

LOOKING

AT

A

BOTTLE
-
NECK

OF

SCALABILITY

IN

CMOS

INDUSTRY
.

REFERENCES

1.
WIKIPEDIA (
www.wikipedia.com
)


2.
YOUTUBE & THE RESPECTIVE CREATORS FOR THE MULTIMEDIA VIDEOS



3. ADDER AND MULTIPLIER DESIGN IN QUANTUM DOT CELLULAR
AUTOMATA
IEEE TRANSACTION JUNE 2009 BY

Heumpil Cho, Member,
IEEE, and Earl E. Swartzlander, Jr., Fellow, IEEE


4. QUANTUM CELLULAR AUTOMATA: THEORY AND APPLICATIONS


BY CARLOS A. P
´
EREZ DELGADO

APPRECIATING

YOUR

PATIENCE

FOR

THIS

INFORMATIVE

SESSION