Advanced Topics:

1
Advanced Topics

• Quantum Computing

2
Peter Phillips, Ross Baker, Scott Brinks
3
Discussing Key Topics

• Introduction to Quantum Computers
• History and concept
• What Quantum Computers are?
• How Quantum Computers work?
• Advantages
• Disadvantages
• Most typical uses
• Cryptography
• Quantum Communication
• Artificial Intelligence
• Large Scale Applications

4
Introduction
5
Introduction

• Although computers have become more compact and
  considerably faster in performing their task, the
  task remains the same
• Manipulate and interpret an encoding of binary
  bits into a useful computational result.

6

• There is one key difference between a classical
  computer and a quantum computer

• A classical computer obeys the well understood
  laws of classical physics

• A quantum computer harnesses physical phenomenon
  unique to quantum mechanics to create a
  fundamentally new method of processing.

7

• Quantum computing is a fairly new science

• The ideas were formulated in the mid-eighties,
  and the first prototypes werent built until the
  mid-to-late-nineties.

• Except for a few basic mathematical
  calculations, all applications associated with
  quantum computing are purely theoretical

8
What is quantum computing?
9
What is quantum computing?

• In a quantum computer, the fundamental unit of
  information (called a quantum bit or qubit), is
  not binary but rather more quaternary in nature.

10

• This qubit property arises as a direct
  consequence of its adherence to the laws of
  quantum mechanics which differ radically from the
  laws of classical physics.

• A qubit can exist not only in a state
  corresponding to the logical state 0 or 1 but
  also in states corresponding to a blend or
  superposition of these classical states

11

• In other words, a qubit can exist as a zero, a
  one, or simultaneously as both 0 and 1, with a
  numerical coefficient representing the
  probability for each state

• This may seem counterintuitive because everyday
  phenomenon are governed by classical physics, not
  quantum mechanics -- which takes over at the
  atomic level

12

• This unique characteristic, among others, makes
  the current research in quantum computing not
  merely a continuation of today's idea of a
  computer, but rather an entirely new branch of
  thought

13
The details(How it works)
14
The details(How it works)

• In a traditional computer, information is encoded
  in a series of bits, and these bits are
  manipulated via Boolean logic gates arranged in
  succession to produce an end result

15

• A quantum computer manipulates qubits by using a
  series of quantum gates, each a unitary
  transformation acting on a single qubit or pair
  of qubits

• In applying these gates in succession, a quantum
  computer can perform a complicated unitary
  transformation to a set of qubits which are in
  some initial state

• The qubits can then be measured, with this
  measurement serving as the final computational
  result

16

• The similarity in calculation between a classical
  and quantum computer suggests that, in theory, a
  classical computer can accurately simulate a
  quantum computer

17

• Can a classical computer do anything a quantum
  computer can?
• If so, why bother with quantum computers?

18

• Although a classical computer can theoretically
  simulate a quantum computer, it is incredibly
  inefficient
• So much so, that a classical computer is
  effectively incapable of performing many tasks
  that a quantum computer could perform with ease

19

• The simulation of a quantum computer on a
  classical one is a computationally hard problem
  because the correlations among quantum bits are
  qualitatively different from correlations among
  classical bits

20
Advantages
21
Speed!

• Quantum Computers have the potential to solve
  certain calculations billions of times faster
  than any silicone-based computer
• Solve problems that would take millions of years
  to figure out using present-day computers

22
Continuity

• Algorithms used in classical computers can be
  directly applied to quantum computers
• Revolutionary concept can be used with current
  framework of computing

23
Disadvantages

• Technology required is currently beyond our reach
• Not practical for certain applications
• (word processing, etc)
• Three obstacles
• Decoherence (quantum decay)
• Error correction
• Hardware architecture

24
Theoretical Uses

• Cryptography
• Large-Scale Applications
• Communication
• Artificial Intelligence

25
Cryptography

• Most common form of encryption is known as RSA
• Relies heavily on factoring huge numbers into
  primes
• Quantum factorization algorithm
• Could break extremely complex code in a matter of
  seconds

26
Large Scale Computing

• Solve complex math algorithms
• Needle-in-a-haystack algorithm
• Exhaustively searching a large set of possible
  solutions
• Large scale database management

27
Artificial Intelligence

• Theories suggest that every physical object in
  the universe is a quantum computer
• If all computers are functionally equivalent then
  computers should be able to model every physical
  process
• Ultimately, computers will be capable of
  simulating conscious rational thought

28
Quantum Communication

• Quantum information cannot be measured without
  disrupting it
• Attempts to eavesdrop on a message would set off
  an alarm
• Automatic shut down of transmission

29
Conclusion

• Based on quantum laws rather than physical laws
• Quantum computers basic building blocks are
  qubits (quantum bits) rather than binary bits
• Some of possible advantages are
• Speed
• very fast applications
• Continuity
• use current algorithms

30
Conclusion

• Some of possible disadvantages are
• Theoretical
• Current technology is out of our reach
• Impractical
• Too fast for common applications
• Some of possible uses are
• Cryptography
• Large Scale Computing
• Artificial Intelligence
• Quantum Mechanics

31
Thanks for listening

• Questions anyone?