Future Computing

8/8/2019 Future Computing

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The Future of Computing

T. Kerdcharoen, T. Osotchan, T. Srikhirin and U. Robkob

Capacity Building Center for Nanoscience and

Nanotechnology

Department of Physics, Faculty of ScienceMahidol University

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OverviewOn

Nanotechnology


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Nanometer = 1/1,000,000,000 meter

1.74 meter

millimeter

micrometer

nanometer

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NanotechnologyThe Founders Point of View

Richard Feynman

Nobel Prize in Physics, 1965

The principles of physics, as far as I can see, do

not speak against the possibility of maneuveringthings atom by atom. It is not an attempt to

violate any laws; it is something, in principle,

that can be done; but in practice, it has not been

done because we are too big

The problems of chemistry and biology

can be greatly helped if our ability to

see what we are doing, and to do things

on an atomic level, is ultimatelydeveloped---a development which I

think cannot be avoided.

There is plenty of room at the

bottom-- Special Lecture in 1959 --


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NanotechnologyThe Nobel Prize Winners Point of View

Nanotechnology has given us the tools to play withthe ultimate toy box of nature - atoms andmolecules. Everything is made from it. Thepossibilities to create new things appear limitless.

Horst Stormer (Nobel Prize in Physics 1998)

Lucent Technologies

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Nanotechnology is the builders final

frontier.

Richard Smalley (Nobel Prize in Chemistry 1996,

Discovery of Bucky Ball) Rice University


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Nanotechnology is the way of ingeniously controlling

the building of small and large structures withintricate properties; it is the way of the future, a

way of precise, controlled building, with

incidentally, environmental benignness built in by

design.

Roald Hoffmann (Nobel Prize in Chemistry)

Cornell University

Picture from NASA

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NanotechnologyThe Futurists Point of View

1800-1900: 1stIndustrial Revolution

Automation Age

1900-1950: Quantum RevolutionAtomic Age

1950-2000: IT Revolution

Electronic Age

2000-2050: Biotech Revolution

Genomic Age

2050-2100: 2ndIndustrial Revolution

Nano Age


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A new playground where physics, chemistry, biology,

computer science, materials science, electrical engineering

and mechanical engineering converge

NanotechnologyOur Own Point of View

Tanakorn Osotchan

Semiconductor Physics

Teerakiat Kerdcharoen

Molecular Computation

Termsak Srikhirin

Materials Science

Udom Robkob

Quantum Physics

Wannapong Triampo

Statistical Physics

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What is Nanotechnology

Capability to manipulate, control,

assemble,produce andmanufacturethings at atomic precision


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What is Nanoscience

Knowledge and understanding of

behavior and phenomena of the

nanoscale world

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The Importance of Scale


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Types of Technology

Bulk Technology

Molecular Technology

- Top-Down technology

- Every human technology including

microelectronics- No atomic resolution

- Bottom-Up technology

- All life technologies, i.e. proteins, DNA, cell

- Atomic resolution- This is Nanotechnology

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Human & Life Technologies Comparison


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Candidates for Future Computing

Mechanical Nanocomputing

Electronic Nanocomputing

Chemical / Biochemical Nanocomputing

Quantum Computing

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Mechanical Nanocomputer

The first mechanical computer was designed by Charles Babbage

(Cambridge University) in 1837 called Difference Engine No. 1

K. Eric Drexler proposed a design of mechanical nanocomputer

based on rods and gears made of molecules in 1988.

Pictures from Acc. Chem. Res. 34 (2001) 445.


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Electronic Nanocomputer

Continue a miniaturization of current electronic computer

Elementary components are based on soft materials, i.e. organicmolecules, semiconducting polymers or carbon nanotubes, instead of

inorganic solid-state materials

Use only 1 or few electrons instead of billion electrons

Use self assembly or other patterning techniques instead of

photolithography

NASA

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Chemical Nanocomputer

Computing is based on chemical reactions (bond breaking and

forming)

Inputs are encoded in the molecular structure of the reactants and

outputs can be extracted from the structure of the products

Adleman proposed DNA computing in 1994 for solving

Hamiltons path problem

Picture from http://www.englib.cornell.edu/scitech/w96/DNA.html


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Quantum Computer

Based on proposals by Bennett, Deutsch and Feynman in 1980s

Use quantum bit (qubit) from the physical properties of materials,i.e. spin state, polarization.

Parallelism in Nature

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Paradigm Shift on Future Computing

From VLSI-based computer(Single Complex System) to lesscomplex ultra-small computing units interconnected as networks, i.e.like in neural networks system (Complex of Simple Systems)

Nanocomputers will be embeded in almost everywhere

From universal computer(Turing Machine) to more task-specificcomputer interconnected to do universal jobs (Cellular Machine)

Matter as Software (Computing is Physical)

Hybrid System


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Hybrid System

Integration between Silicon and Carbon systems

Life and Non-Life Integration

Mechanical, Electronic, Chemical and Quantum Integration

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Moletronics(Molecular Electronics)


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Problems of Present Electronics

When devices become smaller ..

Avalanche breakdown from high electric field over a short distance

(electrons run off track)

Heat dissipation

Vanishing bulk properties and non-uniform doping

Quantum tunnelling in depletion region

Electron leak through thin oxide layer

Picture from MITRE Corp

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Timeline in Moletronics

1974: Aviram & Ratnet proposed a design of molecular rectifier

1977: Discovery of conductive polymer

1987: Kodak developed Organic Light Emitting Diode

1996: Demonstration of conduction in molecule

1997: Discovery of molecular diode

1998: IC from polymer

1999: Molecular switch

2000: Dip-Pen nanolithography

KODAK

Nature Magazine


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Dip-Pen Nanolithography

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Elements of Moletronics Circuit

Basic component of moletronics circuit are:

Molecular Wire

Molecular Diode

Molecular Switch

Picture form MITRE Corp


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Candidates for Molecular Wire

Carbon Nanotube

Conductive polymer

DNA

Metal nanowire ???

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Computational Tools:

Weapons of the Designer

Numerical Simulation

- Molecular mechanics- Molecular dynamics

- Monte Carlo simulation

- Ab initio molecular dynamics

Quantum Calculation

- Molecular orbital calculation

- Density functional calculation

- Semi-empirical quantum calculation

Structural information

Energetics

Dynamical properties

Thermodynamic properties

Electronic structure

Spectroscopic data


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Why Calculation ?

Calculation suggests the engineering limit.

Calculationpredictsproperties of the designed system.

Calculation provides data unreachable by experimental

techniques.

Calculation leads to understanding of nanoscale

phenomena.

The fundamental laws necessary for the mathematical treatment of

a large part of physics and the whole part of chemistry are thus

completely known, and the difficulty lies only in the fact thatapplication of these laws leads to equations that are too

complex to be solved

-- Dirac 1926 --

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Conduction in Molecular Wire

The conduction channel in molecule transport one electron at a time

The conduction channel is represented by delocalized molecular

orbital (MO)

It is still unclear whetherHOMO orLUMO conduct electron

Energy levels (MolecularOrbitals) in molecule

are discrete

HOMO

LUMO(Lowest Unoccupied)

(Higest Occupied)


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Determination of Electronic States

Photoemission Spectroscopy (VUV and Soft X-Rays)

- He I and He II Ultraviolet sources- Synchrotron Radiation (at Nakhon Ratchasima)

Quantum Molecular Calculation

- ab initio methods (Wave Function Methods)

- Density Functional Theory

Picture of Exp. Spectra and Calc. Energy level of C60

from PCCP3 (2001) 4481.

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Determination of Molecular Orbital

National Synchrotron Light Source

- VUV and Soft X-Rays Photoelectron Beamline


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Calculation and Experiment

Chem. Phys. Lett. 321 (2000) pp. 78-82

DFT Calculation

STM Experiment

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Calculation of Near-Fermi States

HOMO

LUMO

HOMO

LUMO LUMO+1

HOMO-1

Delocalized and localized states

A. Udomvech, T. Kerdcharoen, T. Osotchan, Y. Tantirungrotechai and V. Parasuk


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Finite and Discrete at the Nanoscale

0 1 2 3 4 5 6 7 8 9 10 11 12 13-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

Binding

Energy

(eV)

ClosedOpen

(LUMO+1)-open

(HOMO-1)-open

LUMO-closed

HOMO-closed

Number of Unit Cells

The finite-sized nanowire has finite energy gap

The energy gap is smaller as the length increases

0 1 2 3 4 5 6 7 8 9 10 11 12 13-1.0-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

No. of Unit Cell

Eg

(eV)

Open-end (AM1)

Closed-end (AM1)

Open-end (EHMO)

Closed-end (EHMO)

Open-end (B3LYP/CEP-31G)

Closed-end (B3LYP/CEP-31G)

A. Udomvech, T. Kerdcharoen, T. Osotchan, Y. Tantirungrotechai and V. Parasuk

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Calculation Test of Molecular Diode

The idea is tested by Density Functional Theory

HOMO

LUMO

Donor

Acceptor


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Molecular Electronics: AND Gate, OR Gate


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Molecular Electronics: Adder



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How Big Can We Simulate now ?

Nanosystem has a length scale between 1-100nanometer

A nanoscale cube (L=100 nm) has approximately1 billion atoms

Current capacity for typical classical simulation(scale as N2) is less than 1 million atoms

Current capacity for typical quantum simulation(scale as N3 -N7) is less than 500 atoms

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Dependence of Nanotechnology

Advance in Nanotechnology

Advance in

Nanoelectronics

Advance in Computer

Advance in

Simulation


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Future Computing

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