Moore’s LawMoore’s Lawthe number of circuits on a the number of circuits on a single silicon chip doubles single silicon chip doubles every 18 to 24 months every 18 to 24 months

Anticipating ProblemsAnticipating Problems

Minimum size of transistors or else will not work reliably

Power leakage produces heat

What now?What now?

How do we create a better How do we create a better computer?computer?

Innovate.Innovate.

more instruction pipelinesmore instruction pipelines

more registersmore registers

more specialized circuitrymore specialized circuitry

More innovations…More innovations…

improve instruction setimprove instruction set

bigger on-chip cachebigger on-chip cache

What’s next?What’s next?

DNA computingDNA computing

Quantum computingQuantum computing

Molecular computingMolecular computing

Optical computingOptical computing

DNA Computing DNA Computing

illustrates possibilities of using illustrates possibilities of using DNA to solve problemsDNA to solve problems

example of computation at a example of computation at a molecular levelmolecular level

demonstrates unique aspects of demonstrates unique aspects of DNA as a data structureDNA as a data structure

computing with DNA can work in computing with DNA can work in a massively parallel fashiona massively parallel fashion

DNA: unique data DNA: unique data structurestructure uses four nucleic acids instead of uses four nucleic acids instead of

binary ones and zeroes(0,1 A,T,C,G)binary ones and zeroes(0,1 A,T,C,G)

high data density – bases are spaced 0.35nm = 18Mbits per inch in 1D

= 1mil Gbits per sq inch in 2D

double stranded nature.

DNA vs. SiliconDNA vs. Silicon

DNA is modified by a variety of DNA is modified by a variety of enzymes which do not function enzymes which do not function sequentiallysequentially

Just like CPU has addition, bit-Just like CPU has addition, bit-shifting, logical operators (AND shifting, logical operators (AND OR NOT NOR) DNA has cutting, OR NOT NOR) DNA has cutting, copying, pasting, repairing, etc.copying, pasting, repairing, etc.

Useful in the studies Useful in the studies of:of: LogicLogic EncryptionEncryption Genetic programming and Genetic programming and

algorithmsalgorithms AutomataAutomata Language systemsLanguage systems

Quantum ComputingQuantum Computing

Beyond the ordinary binary Beyond the ordinary binary “on” and “off” (represented by 1 “on” and “off” (represented by 1 and 0), quantum computing has a and 0), quantum computing has a third state that is both 1 and 0 at third state that is both 1 and 0 at the same timethe same time

Quantum InterferenceQuantum Interference

Quantum InterferenceQuantum Interference

Quantum InterferenceQuantum Interference

The Quantum BitThe Quantum Bit

One qubit can encode at a given One qubit can encode at a given moment of time both 0 and 1moment of time both 0 and 1

Registers composed of qubits can Registers composed of qubits can store greater information at oncestore greater information at once

Quantum computer offers Quantum computer offers enormous gain in the use of enormous gain in the use of resources such as time and resources such as time and memorymemory

Simple quantum gatesSimple quantum gates

Simple quantum gatesSimple quantum gates

Simple quantum gatesSimple quantum gates

Other featuresOther features

QuantizationQuantization - observable quantities - observable quantities do not vary continuously but come in do not vary continuously but come in discrete chunks or 'quanta'discrete chunks or 'quanta'

EntanglementEntanglement - Two spatially - Two spatially separated and non-interacting quantum separated and non-interacting quantum systems that have interacted in the past systems that have interacted in the past may still have some may still have some locally inaccessible locally inaccessible informationinformation in common - information in common - information which cannot be accessed in any which cannot be accessed in any experiment performed on either of them experiment performed on either of them alone alone

Problem: DecoherenceProblem: Decoherence

Surrounding environment is Surrounding environment is affected by the interactions that affected by the interactions that generate quantum superpositionsgenerate quantum superpositions

Quantum computation will spread Quantum computation will spread outside the computational unitoutside the computational unit

Will irreversibly dissipate useful Will irreversibly dissipate useful information to the environment information to the environment

Promising futurePromising future

Grover’s search algorithmGrover’s search algorithm

Shor’s factorization algorithmShor’s factorization algorithm

Important applicationsImportant applications

Cryptography: perfectly secure Cryptography: perfectly secure communicationcommunication

Searching, especially algorithmic Searching, especially algorithmic searching (Grover's algorithm)searching (Grover's algorithm)

Factorizing large numbers very Factorizing large numbers very rapidly (Shor's algorithm)rapidly (Shor's algorithm)

Simulating quantum-mechanical Simulating quantum-mechanical systems efficientlysystems efficiently

Molecular ComputingMolecular Computing

Use of molecules as transistors, Use of molecules as transistors, allowing chips to hold billions or allowing chips to hold billions or trillions of switches and trillions of switches and componentscomponents

Comparing to SiliconComparing to Silicon

very easy and cheap to makevery easy and cheap to make Molecules only a few nanometers Molecules only a few nanometers

in sizein size Cheaper non-volatile memoryCheaper non-volatile memory