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8/8/2019 Future Computing
1/23
1
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
2
OverviewOn
Nanotechnology
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Nanometer = 1/1,000,000,000 meter
1.74 meter
millimeter
micrometer
nanometer
4
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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NanotechnologyThe Nobel Prize Winners Point of View
Nanotechnology is the builders final
frontier.
Richard Smalley (Nobel Prize in Chemistry 1996,
Discovery of Bucky Ball) Rice University
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NanotechnologyThe Nobel Prize Winners Point of View
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
Picture form MITRE Corp
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Molecular Electronics: Adder
Picture form MITRE Corp
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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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