QUANTUM COMPUTERS   

   

SUBMITTED BY Mr. Nolesh Premraj Warke.

ABSTRACTThe subject of quantum computing brings together ideas

from classical information theory, computer science, and quantum physics.

Quantum Computing merges two great scientific revolutions of the 20th century: Computer science and Quantum physics.

Quantum devices rely on the ability to control and manipulate binary data.

Quantum computing is the design of hardware and software that replaces Boolean logic by quantum law at the algorithmic level.

INTRODUCTIONWhat is Quantum computer ?

A quantum computer is a machine that performs calculations based on the laws of quantum mechanics,

which is the behavior of particles at the sub-atomic level.

A Quantum is a smallest possible discrete unit of any physical property Quantum Computing.

Computation depends on principle of quantum theory.

Exploit properties of quantum physics

Built around “qubits” rather than “bits”

Operates in an extreme environment.

Quantum approach is thousand a times faster.

Where did this idea come from ?

1982Richard Feynman envisions quantum computing

1985David Deutsch describes universal quantum computer

1994Peter Shor develops algorithm that could be used for quantum code-breaking

1999D-Wave Systems founded by Geordie Rose

2010D-Wave One: first commercial quantum computer, 128 qubits

2013D-Wave Two,

512 qubits

26th JAN 2017D-Wave 2000Q,

2000 qubits

Why Quantum Computing?

"The number of transistors incorporated in a chip will approximately double every 24 months." 

-- Gordon Moore, Intel Co-Founder

Why Quantum Computing? By 2020 to 2025, transistors will be so small and it

will generate so much heat that standard silicon technology may eventually collapse.

Already Intel has implemented 32nm silicon technology

If scale becomes too small, Electrons tunnel through micro-thin barriers between wires corrupting signals.

Beauty of Quantum TheoryQuantum Mechanical theories are totally

different from the point of common sense.

But it agrees fully with experimental facts.

This is the beauty of Quantum Mechanics.

Literature surveyQuantum computers unlike classical computers

make use of qubits.

Qubits are nothing but Quantum bits.

Classical computers make use of classical bits.

Classical bits used in classical computers store single binary value at a single instance i.e. 0 or 1.

Qubits can store combination of 0 and 1 which can multiply the speed of processing into n times than that of classical computers.

These Qubits help Quantum computers to solve impractical or impossible to solve for a classical computer.

Traveling Salesman Problem: It is one of the best example for explaining

working of a quantum computer and speed as well.

A salesman always tries to figure out the shortest route to travel.

Here the conventional computer will compute for each and every route and will give the optimized route to the salesman which is very time consuming.

Quantum computers make use of qubits as they can represent more than one thing simultaneously i.e. they can work parallel.

This means Quantum computers can try insane

number of routes at the same time and return the answer in seconds.

A problem having n number of cities to be traveled to computed the shortest distance a classical computer will require 100’s or 1000’s of years, but a Quantum computer can work for it within seconds or minutes.

Algorithms Used David Deutsch (1992): It is an

Deterministic Quantum algorithm. Determine whether f: {0,1}n→ {0,1} is constant or balanced using a quantum computer

Daniel Simon (1994): Special case of the abelian hidden subgroup problem

Peter Shor (1994): Given an integer N, find its prime factors

Lov Grover (1996): It is an optimization

algorithm. Search an unsorted database with N entries in O(N1/2) time

Quantum properties used:

Superposition De coherence Entanglement Uncertainty principle Linear algebra Dirac notation

Superposition Property to exist in multiple states.

In a quantum system, if a particle can be in states |A and |B, then it can also be in the state 1|A + 2|B ; 1 and 2 are complex numbers.

Totally different from common sense.

De coherence The biggest problem.

States that if a coherent (superposed) state interacts with the environment, it falls into a classical state without superposition.

So quantum computer to work with superposed states, it has to be completely isolated from the rest of the universe (not observing the state, not measuring it, ...)

Most important property in quantum information.

States that two or more particles can be linked, and if linked, can change properties of particle(s) changing the linked one.

Two particles can be linked and changed each other without interaction.

Entanglement

PROCESSOR ENVIRONMENT: Cooled to 0.015 Kelvin (-

275ºC), 175x colder than interstellar space in order to keep noise and interference to a minimum.

On low vibration floor

<25 kW total power consumption – for the next few generations

Architecture

Shielded to 50,000× less than Earth’s magnetic field

In a high vacuum: pressure is 10 billion times lower than atmospheric pressure

16 Layers between the quantum chip and the outside world

Shielding preserves the quantum calculation

Processing A lattice of superconducting

loops (qubits)

Chilled near absolute zero to quiet noise

User maps a problem into

search for “lowest point in a vast landscape” which corresponds to the best possible outcome

Processor

Processor considers all possibilities simultaneously to satisfy the network of relationships with the lowest energy

The final state of the qubits yields the answer

Software Environment

Programming Environment Operates in a hybrid mode with a HPC System or Data

Analytic Engine acting as a co-processor or accelerator A system is “front-ended” on a network by a standard

server (Host)

User formulates problem as a series of Quantum Machine Instructions (QMIs)

Host sends QMI to quantum processor (QP) QP samples from the distribution of bit-

strings defined by the QMI

Results are returned to the Host and back to the user

The Use OF quantum computers Good for complex calculations Public key Cryptography Data Encryption

For data encryption of 1024 bite code it needs 3000 years for a classical computer and a minute for Quantum computer.

Data security

AdvantagesCould process massive amount of complex data.Ability to solve scientific and commercial problems.Process data in a much faster speed.Capability to convey more accurate answers.More can be computed in less time.MUCH MORE…..

DisadvantagesDe coherence (must be isolated)Uncertainty Principle (Can’t measure without disturb)Ability to crack passwordsCan Break every level of encryptionComplex Hardware SchemesCost

What can Quantum Computer do?Application : Factorization (data security) Physical modelling (climate , economic ,

engineering) Simulation (chemistry ,material) Data bases searching (bioinformatics) Parallel Processing

Future Scope

Health

Finance Computing

Space

Cancerresearch

Anomalydetection

And many more….

Powerful new resource for computation

Complementary to classical computers

Accessible via the cloud

Emergence of quantum software ecosystem

Developer tools Optimized algorithms Applications

Yes ! A Quantum Computer can perform tasks we couldn’t hope to perform with ordinary digital computers….

D-Wave 2000Qubits Quantum Computer

Quantum Chip

"When you change the way you look at things, the things you look at change.” Max Planck, Father of Quantum Physics

[1] P.K. Amiri "quantum computers" IEEE Potentials ( Volume: 21, Issue: 5, Dec 2002/Jan 2003 )

Dept. of Electr. Eng., Sharif Univ. of Technol., Tehran, Iran

[2] David Deutsch, ``Quantum Computational Networks'', Proc. Soc. R. Lond. A400, pp. 97-117, 1985.

[3 Peter. W. Shor, ``Polynomial-Time Algorithms For Prime Factorization and Discrete Logarithms on a

Quantum Computer'', 35th Annual Symposium on Foundations of Computer Science, pp. 124-134

[4] The excitonic quantum computer F. Rossi IEEE Transactions on Nanotechnology Year: 2004,

Volume: 3, IEEE Journals & Magazines

[5] R. W. Keyes “Challenges for quantum computing with solid-state devices” Computer

Year: 2005, Volume: 38

[6] C. P. Williams “Quantum search algorithms in science and engineering”

Computing in Science & EngineeringYear: 2001, Volume: 3

References

[7] Quantum computing: the final frontier? R. J. Hughes; C. P. Williams IEEE Intelligent Systems and their Applications Year: 2000, Volume: 15

[8] G. Fairbanks, D. Garlan, and W. Scherlis, "Design fragments make using frameworks easier," in Proceedings of the 21st annual ACM SIGPLAN conference on Object-oriented programming systems, languages, and applications Portland, Oregon, USA: ACM, 2006.

[9] N. D. Mermin, “Quantum Computer Science: An Introduction,” 1 ed. Cambridge,

UK: Cambridge University Press, 2007.

[10] R. J. Hughes; C. P. Williams "Quantum computing: the final frontier" .IEEE Intelligent Systems and their Applications Year: 2000, Volume: 15

[11] L. Grover, ``A Fast Quantum Mechanical Algorithm for Database Search'' Symposium on Theory of Computing - STOC-96, pp. 212-219, 1996..

[12] [Childs2002]. A. M. Childs, E. Farhi, and J. Preskill, ``Robustness of adiabatic quantum computation'', Phys. Rev. A65, 2002, quant-ph/0108048

[13] https://en.wikipedia.org/wiki/Quantum_computing

[14] http://www.qubitapplications.com

[15] https://www.dwavesys.com/

[16] Bulk Spin Resonance Quantum Computation http://feynman.stanford.edu

Thank you

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