This document discusses quantum computers and their advantages over classical computers. It begins by describing classical computers and how they operate based on classical mechanics. It then defines quantum computers, explaining that they use quantum bits that can exist in superposition and entanglement, allowing them to perform multiple computations simultaneously. The document outlines the history of quantum computing development. It also discusses quantum computing concepts like superposition and entanglement. Finally, it reviews some applications of quantum computing like simulation, encryption, and factorization algorithms.

1. SHAIK NAGUR SHAREEF
B.Tech-CSE(161FA04195)
VIGNAN’S UNIVERSITY
QUANTUM COMPUTERS
Latest Technology for Bright Future

2. Areas of Discussion
o Classical Computers
o Quantum Computers
o History & Definition
o Basic principles
o Algorithms
o Abilities
o Applications
o Conclusion
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3. Classical Computers
These are made of transistors and diodes
In these, the data is encoded into binary digits (bits)
Performs calculations based on the laws of classical mechanics
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Makes work easy and faster
Complex Computation or Logical work become easy
Accurate and Speedy Computation machine
Many kinds of numerical problems cannot be solved using conventional
computers
 example: factorization of a number
The computer time required to factor an integer containing N digits is
believed to increase exponentially with N.

5. History
1985 - david deutsch -university of oxford, describes -first universal quantum computer
1993 - dan simon, a-universite de montreal-invents an oracle problem for which quantum
computer would be exponentially faster than conventional computer.
This algorithm introduced the main ideas which were then developed in peter shor's factoring
algorithm.
1996 - lov grover, at bell labs, invents quantum database search algorithm
1998 - first working 2-qubit NMR computer demonstrated at university of california, berkeley
1999 - first working 3-qubit NMR computer demonstrated at ibm's almaden research center.
First execution of grover's algorithm
2000 - first working 5-qubit NMR computer demonstrated at ibm's almaden research center.
2001 - first working 7-qubit nmr computer demonstrated at ibm's almaden research center.
First execution of shor's algorithm. The number 15 was factored using 1018 identical
molecules, each containing 7 atoms.
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6. Quantum computer
Quantum Computers make direct use of Quantum-mechanical
phenomena such as Superposition and Entanglement to
perform operations on data
Quantum Computation uses Quantum bits (qubits) which can be
in superposition states.
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7. Data representation (qubit)
Qubit is a unit of Quantum Information.
Different physical objects can be used as qubits such as Atoms,
Photons or Electrons
Exists as a ‘0’, a ‘1’ or simultaneously as a superposition of both
‘0’ & ‘1’
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8. Quantum superposition
An electron has dual
nature (particle and wave)
Wave exhibits a
phenomenon known as
superposition
This allows the addition
of waves numerically
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9. Quantum entanglement
Measurement of one
particle will effect the state
of another particle, though
classically there is no
direct interaction
When this happens, the
state of the two particles is
said to be entangled
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10. Quantum dots
 A technology that enables ‘Qubits' to exist as
Coherent-Superposition of 0 and 1 states is ‘Quantum
Dots’
When the dot is exposed to a pulse of laser light of
the right wavelength & duration, the electron is raised to
an excited state: a second burst of laser light causes
the electron to fall back to its ground state
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11. Quantum teleportation
Quantum teleportation is a
technique used to transfer
information on a quantum level,
usually from one particle to
another.
Its distinguishing feature is that
it can transmit the information
present in a quantum
superposition, useful for
quantum communication and
computation.
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12. Quantum parallelism
Quantum Computer is able to perform two or more computations
simultaneously at once
Single quantum processor is able to perform multiple
computations
In classical computers, parallel computing is performed by having
several processors linked together
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13. Algorithms
Shor’s algorithm (factorial if n digited number at polynomial time
‘F(a) = x mod N’)
Grover’s algorithm (search a name in unsorted database)
 Chaos SAT algorithm
Adaptive SAT algorithm
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15. Applications
Quantum networking
Encryption
Ultra-secure & Super-dense Communications
Molecular Simulations
True Randomness
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16. Conclusion
Quantum computing could provide a radical change in the way
computation is performed.
The advantages of quantum computing lie in the aspects of
quantum mechanics that are peculiar to it, most notably
entanglement.
 Classical computers will be significantly larger than quantum
computers for the foreseeable future
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