Presented By:

Krishna M Patel - 120080116038

Priyanka G Patel - 120080116037

INDEX Computer Generation

History

Defination

Why Quantum computing??

introduction of Qubits

How powerful are quantum computers

Quantum algorithms

Application

Advantages and Disadvantages

Present status

Conclusion

First Generation (1940-1956)

Vacuum Tubes

Second Generation (1956-1963)

Transistors

Third Generation (1964-1971)

Integrated Circuits

Fourth Generation (1971-present)

Microprocessors

Fifth Generation (Present and Beyond)

Artificial Intelligence

Year Scientist Research

1982 Feynman Idea of creating machines

based on the laws of

quantum mechanics

instead of the laws of

classical physics.

1985 David Deutsch Developed the quantum

turing machine, showing

that quantum circuits are

universal.

1994 Peter Shor A quantum algorithm to

factor very large numbers

in polynomial time.

1997 Lov Grover Develops a quantum search

algorithm with O(√N)

complexity

History:

Quantum computing is the area of study focused on developing computer technology based on the principles of quantum theory, which explains the nature and behaviour of energy and matter on the quantum (atomic and subatomic) level.

Quantum Computer:

A quantum computer is a computation device that makes direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data.

By 2020 we will hit natural limits on the size of transistors

Max out on the number of transistors per chip

Reach the minimum size for transistors

Reach the limit of speed for devices

Eventually, all computing will be done using some sort of alternative structure

DNA

Cellular Automation

Quantum

In quantum computing, a qubit or quantum bit is a unit of quantum information.

Qubits represent atoms, ions, photons or electrons and their respective control devices that are working together to act as computer memory and a processor.

A qubit is a two-state quantum-mechanical system.

Vertical polarization

Horizontal polarization

A qubit has a quantum register.

Similar to qubit, a qutrit, qudit is also used for other level quantum system.

The two states in which a qubit may be measured are known as basis states.

They are represented by Dirac notation.

States are conventionally written as |0> and |1>:

An excited state representing |1> and a ground state representing |0>.

|ѱ>=α|0> + β|1>,

When we measure this qubit in the standard basis, the probability of outcome for |0> is |α|2 and outcome for |1> is |β|2.

|α|2 + |β|2 = 1

Operation on qubits:

unitary transformation

Standard basis measurement

Excited

State

Ground

State

Nucleus

Electro

nState

|0>

State

|1>

Bits:

The device computes by manipulating those bits with the help of logical gates.

A classical computer has a memory made up of bits, where each bit holds either a one or a zero.

Qubits:

The device computes by manipulating those bits with the help of quantum logic gates.

A qubits can hold a one,a zero or crucially a superpositoion of these.

A single qubit can be forced into a superposition of the two states denoted by the addition of the state vectors:

A qubit in superposition is in both of the states |1> and |0> at the same time.

DEFINITION

Two things can overlap each other without interfering with each other.In classical computers,electrons cannot occupy the same space at the same time.

Entanglement is the ability of quantum systems to exhibit correlation between states within a superposition.

Imagine two qubits,each in the state |0>+|1>(a superposition of 0 and 1).We can entangle the two qubits such that the measurement of one qubit is always correlated to the measurement of other qubit.

Some of quantum algorithms can turn hard mathematical problems into easy ones.

The time takes to execute the algorithm must increase no faster than a polynomial function of the size of the input.

Potential use of quantum factoring for code-breaking purpose has raised the suggestion of building a quantum computer.

It may help in cryptography.

A quantum algorithm is an algorithm which runs on a realistic model of quantum computation.

Quantum algorithm is a step-by-step procedure.

ALGORITHM

I. Jozsa algorithm

II. Simon’s algorithm

III. Shor’s algorithm

Jozsa algorithm:

This algorithm solves a black-box problem which probably requires exponentially many queries to the black box for any deterministic classical computer, but can be done with exactly 1 query by quantum computer.

Simon’s algorithm:

This algorithm solves a black-box problem exponentially faster the any classical algorithm, including bounded-error probabilistic algorithms.

Shor’s algorithm:

This algorithm solves the discrete logarithm problem and integer factorization problem in polynomial time, whereas the best known classical algorithms take super-polynomial time.

Even though no quantum computer has been built that hasn’t stopped the proliferation of papers on various aspects of the subject.Many such papers have been written defining language specification.

QCL –(Bernhard-omer)like C syntax and very compelet.

qGCL –(Paolo Zuliani and others)

Quantum C-(Stephen Blaha)Currently just a specification.

Quantum computer can be used in cryptography.

Modelling and indexing of very large databases.

It can be used to solving complex mathematical problems.

Military searches of quantum computer.

Google image search.

Teleportation

Improved error correction and error detection.

Quantum cryptography describes the use of quantum mechanical effects to perform cryptographic tasks or to break cryptographic systems.

Well-known examples of quantum cryptography are the use of quantum communication to exchange a key securely and the hypothetical use of quantum computers that would allow the breaking of various popular public-key encryption and signature schemes.

The advantage of quantum cryptography lies in the fact that it allows the completion of various cryptographic tasks that are proven or conjectured to be impossible using only classical.

The most well known and developed application of quantum cryptography is quantum key distribution (QKD).

Advantages Disadvantages

Increase in computing power Although qubit can hold many possible

values but only one classical result can be

obtained from every run.

Advance in security Repeated runs may be necessary to obtain

the desired result.

Teleportation It is impossible to copy qubits(no-cloning

theorem).

Advantages and Disadvantage of Quantum computing

Quantum physicists from the university of Innsbruck have set another world record: They have achieved controlled entanglement of 14 quantum bits and, thus realized the largest quantum register that has ever been produced.

Researchers at delft University of technology have succeeded in carrying out calculations with two qubits.

December 19, 2001-IBM performs shor’s algorithm.

It discusses the inevitability of quantum computers, how they originated, and what is different about them from classical computers

It is is intended to be accessible to the general people, so it will explain the basics of a few quantum computer features at the risk of over-simplification

Quantum computes are coming, and they will require a new way of looking at computing

If large-scale quantum computers can be built, they will be able to solve certain problems much faster than any classical computer using the best currently known algorithms(for example integer factorization using shor’s algorithm or the simulation of quantum many-body systems).

Desktop quantum computers expected by many within 10 years.