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QUANTUM COMPUTING
Bismillah Ir Rehman Ir Raheem
Lets say a salesman has to travel to many cities in order to sell his
products, and he wants to work out the shortest possible route. In order to
solve this problem, lets assume the No of Cities he wants to travel to as X
and the no of possible routes as Y. Plotting both these variables on a graph
will show a linear relationship as depicted on the slide. As per the graph, if
he wants to visit 14 cities, he has a possible number of routes as 1011
. Of
course, this calculation is not humanly possible, so we take help from
computers. For a classical 1 GHz computer, which carries out calculations
at the rate of 10 9
per second, it would take 100 seconds to solve this
problem. Seemingly, there is no problem at hand. The problem arises if he
has to visit more cities, say 22 cities, then the number of possible routes
increases exponentially to 1019
. Now, it would take 1600 years for that
same 1 GHz computing speed computer to solve this problem. If we
increase the number of cities further, the complexity of the problem
escalates and modern day computers will not be able to solve such
problems in finite time. So, what’s the solution then …….. The answer lies
in QUANTUM COMPUTING

Gentlemen, the aim of my presentation is to apprise the house regarding
the concept of quantum computing, its developmental history, and its
applications that may shape the way we visualize the future.
The Sequence of my presentation will be as shown on the slide
Definition
To understand the definition of quantum computing, let me get you up to
speed
Computation
First of all, Computation is a process following a well-defined model that is
understood and can be expressed in an algorithm, protocol, network
topology, etc. In a general way, we can define computing to mean any
goal-oriented activity requiring, benefiting from, or creating computers. The
list is virtually endless, and the possibilities are vast. As in classical
computers transistors are used which may be in ON or OFF state i.e. either
‘1’ or ‘0’ which are classical bits used for computing, process data, store
data etc. The whole classical computing is based on just ‘0’ or ‘1’.
A Quantum is a smallest possible discrete unit of any physical property

Quantum mechanics is the body of scientific laws that describe the wacky
behavior of photons, electrons and the other particles that make up the
universe.
Quantum computing is essentially harnessing and exploiting the amazing
laws of quantum mechanics to process information. A traditional computer
uses long strings of “bits,” which encode either a zero or a one. In Quantum
Computing, Quantum bits are used which have some special properties. A
Quantum bit or ‘Qubit’ is a unit of quantum information which may be ‘1’ or
‘0’ or ‘Both’ at a same time. Many differentphysical objects can be used as
qubits such as atoms, photons, or electrons.
A Quantum Computeris a machine that performs calculations based on the
laws of quantum mechanics which is behavior of particles at subatomic
level.
Concept
Gentlemen, since the concept of Quantum Computing is new and hard to
grasp, I would like to take you all through a crash course on the subject, so
here is Quantum Computing 101.

Scientists around the world have spent the last decade exploring the
exciting and utterly bizarre place where computer science and quantum
physics collide, so where is that exactly ! Think about quantum computing
like a subway map with two train lines; the Quantum Physics Local and the
Computer Science Express, coming from different directions to meet at a
central hub ‘Station Q’. On the map, the two lines meet and continue
forward together. Now no one knows exactly where they’re headed. Thanks
to brilliant minds from Newton to Einstein, we have a pretty solid
understanding of matter, motion, time, space and how the universe
generally functions. But over the last hundred or so years, scientists looking
closely on life on an atomic and subatomic level, started noticing some
inconsistencies with traditional physics. Questions and theories started
piling up about how and why particles seem to behave predictably on a
large scale like plants, birds, rocks and things. But on the nano scale, its
well …… particles go wild ! It turns out, the behaviours that seem
impossible to imagine on a human scale are downright pedestrian at a
molecular level. Down there, particles, little balls of solid matter, act like
waves. Particles teleport from one place to another and can also become
entangled, making it impossible to separate them. In a quantum state,

particles can even achieve something we call superposition, where they
exist in multiple states simultaneously. Now, you’ve ridden this line many
times before. You know the laptop on your desk, the smartphone in your
hand and the tablet in your bag, all work with information in the form of bits.
Bits, which can either be a 1 or a 0, are arranged in long artful strings to get
computers to do all sorts of things, like sequence DNA or fling angry little
birds at pig-built fortresses. But classical computers have limits to their
problem solving prowess, there are some problems so difficult that even if
all the computers in the world worked on the problem in tandem, it would
still take them a very long time to solve it. So here’s where things get really
interesting and where quantum computing could come in handy. Quantum
Computers run on quantum bits or ‘Qubits’. Because of the mind bending
properties of their quantum state like superposition, a qubit can be a 1 or a
0 or it can exist as a 1 and a 0 at the same time. If one qubit which is a 1
and a 0 can perform two calculations, then two qubits can do four, four can
do eight, and the computing power has the potential to grow exponentially.
With long strings of qubits performing calculations, problems that would
take today’s computers eons to solve, could be solved in the time it takes to
grab a cup of coffee. This could have your wildest imagination type
applications in fields such as machine learning and medicine, chemistry

and chronography, Materials Science and engineering, and could allow
humans to understand and control the very building blocks of the universe.
Qubit
A quantum computer uses quantum bits, or qubits. A qubit is a quantum
system that encodesthe zero and the one into two distinguishable quantum
states. The possible states for a single qubit can be visualized using a
Bloch sphere. Represented on such a sphere, a classical bit could only be
at the “North Pole” or the “South Pole”, in the locations where |0> and |1>
are respectively. The rest of the surface of the sphere is inaccessible to a
classical bit, but a pure qubit state can be represented by any point on the
surface. For example the pure qubit state {|0 > + i|1 > / {sqrt{2}} would lie
on the equator of the sphere, on the positive y axis.
Qubits can either exist in a 0 state or a 1 state, or in a superimposed state.
Quantum Mechanical Phenomena
Quantum Computers use essential quantum mechanical phenomena- It’s
OK to be a bit baffled by these concepts,since we don’t experience them in
our day-to-day lives. It’s only when you look at the tiniest quantum particles

– atoms, electrons, photons and the like – that you see intriguing things like
superposition, entanglement and interference.
• Superposition
An electron has dual nature. It can exhibit as a particle and also as wave.
Wave exhibits a phenomenon known as superposition of waves. This
phenomena allows the addition of waves numerically. Superposition is
essentially the ability of a quantum system to be in multiple states at the
same time — that is, something can be “here” and “there,” or “up” and
“down” at the same time. One example of a two-state quantum system is
the polarization of a single photon
• Entanglement
In Quantum Mechanics, it sometimes occurs that a measurement of one
particle will effectthe state of another particle, even though classically there
is no direct interaction. When this happens, the state of the two particles is
said to be entangled. Entanglement is an extremely strong correlation that
exists between quantum particles — so strong, in fact, that two or more
quantum particles can be inextricably linked in perfect unison, even if
separated by great distances.

Interference
In some cases, particles can cancel each other out in unexpected ways
known as interference. One illustration is a classic physics experiment
called the double-slit experiment. In it, two laser beams (made up of
photons), are shot through thin slits in a metal plate and land on a screen
behind it. In certain places, two photons shot through the slits can collide
and cancel each other out, leading to some blank spots on the screen in
which no photons land.

History
Looking at the chronological development of Quantum Computing:
In 1981, Richard Feynman of Caltech, a Nobel Laureate, proposes a basic
model for a quantum device. He proposed the idea of using quantum
phenomena to perform computations.
In 1985, David Deutsch of Oxford University describes the first "Universal
Quantum Computer". He suggested that quantum gates could function in a
similar way to traditional binary logic gates.
In 1994,Peter Shor devises an algorithm that could allow quantum devices
to defeatcryptography. This algorithm allows a quantum computer to factor
large integers quickly, and could hence potentially break several
cryptosystems used today.
In 1996, at Bell Labs, Lov Grover discovered what is now known as
Grover’s algorithm. This quantum algorithm, allows a quantum computer to
search an unsorted database at a much faster speed than a classical
computer.

In 1998, the First working two- and three-qubit Nuclear Magnetic
Resonance (NMR) quantum computers were demonstrated
In 2001,researchers demonstrated Shor's algorithm to factor 15 using a 7-
qubit NMR computer
In 2006, Scientists at MIT develop the first working 12-qubit platform
In 2009, First universal programmable quantum processor is unveiled by
National Institute of Standards & Technology using 2 qubits of information
In 2011, D-Wave Systems announced the first commercial quantum
annealer, the D-Wave One, claiming a 128 qubit processor.
In 2012, D-Wave Systems reveals a 512-qubit adiabatic quantum machine
known as D Wave Two
In October 2012, Nobel Prizes were presented to David J. Wineland and
Serge Haroche for their basic work on understanding the quantum world,
which may help make quantum computing possible.

In December 2012, the first dedicated quantum computing software
company, 1QBit was founded in Vancouver, BC.[67] 1QBit is the first
company to focus exclusively on commercializing software applications for
commercially available quantum computers, including the D-Wave Two.
In December 2014, researchers at University of New South Wales used
silicon as a protectant shell around qubits, making them more accurate,
increasing the length of time they will hold information and possibly made
quantum computers easier to build.

Process /technologies Involved
Due to technical obstacles, till date, a practical quantum computer has not
yet been realized. But the concepts and ideas of quantum computing has
been demonstrated using various methods. Here, are five most important
technologies used to demonstrate quantum computing:
Nuclear Magnetic Resonance
Using nuclear magnetic resonance (NMR) techniques, invented in the
1940's and widely used in chemistry and medicine today, these spins can
be manipulated, initialized and measured. Most NMR applications treat
spins as
little "bar magnets", whereas in reality, the naturally well-isolated nuclei are
non-classical objects.The spin manipulation is accomplished byapplication
of magnetic pulses within a magnetic field produced by the NMR chamber.
Ion Trap
An Ion Trap quantum computer is also based on control of nuclear spin. In
this approach the individual ions are, as the name implies, trapped or
isolated by means of an electromagnetic field which is produced by means

of an electromagnetic chamber. The trapped ions are cooled to the point
where motion is essentially eliminated.
Quantum Dot
An example of an implementation of the qubit is the 'quantum dot' which is
basically a single electron trapped inside a cage of atoms. A quantum dot is
a particle of matter so small that the addition or removal of an electron
changes its properties in some useful way. When the dot is exposed to a
pulse of laser light of precisely the right wavelength and 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. The ground and excited states
of the electron can be thought of as the 0 and 1 states of the qubit and the
application of the laser light can be regarded as a controlled NOT function
as it knocks the qubit from 0 to 1 or from 1 to 0.
Optical Method
As the name indicates, an optical quantum computer uses the two different
polarizations of a light beam to represent two logical states. As an example,
we can consider the polarization of a light beam in the vertical plane to
represent a logical 1 and the polarization of the beam in the horizontal
plane to represent a logical 0. An Optical quantum computer would be

based on manipulating the polarization of individual photons. Entanglement
is achieved by coincident creation of identical photons. Identical photons in
this context would mean photons having the same energy as well as same
polarization. The superposition of polarization or phase state is
manipulated using polarizing lenses, phase shifters, and beam splitters.
Computing liquids
The quantum computer in this technology is the molecule itself and its
qubits are the nuclei within the molecule. Computing Liquids technique
does not however use a single molecule to perform the computations; it
instead uses a whole 'mug' of liquid molecules. The advantage of this is
that even though the molecules of the liquid bump into one another, the
spin states of the nuclei within each molecule remain unchanged.
Present State of Quantum Computing
The Three big giants of the IT World, IBM, Microsoft and Google have
embarked upon individual paths for the quest of a practical quantum
computer which may take them leaps ahead of their contemporaries

Microsoft is working with universities around the world to develop the first
quantum computer—a topological quantum computer. The unique basis of
this approach to quantum computation is to use topological materials that
by their nature limit errors. These are exotic, low-temperature systems that
possess degrees of freedom that are immune to the action of local
operators. By their topological nature, individual qubits and quantum gates
are protected from errors.
IBM’s investment is one of the largest for quantum computing to date
amounting to $3 Bn; the new R&D initiatives fall into two categories:
Developing nanotech components for silicon chips for big data and cloud
systems, and experimentation with "post-silicon" microchips. This will
include research into quantum computers which don’t know binary code,
neurosynaptic computers which mimic the behavior of living brains, carbon
nanotubes, graphene tools and a variety of other technologies.
Together with NASA, Google co-invested in a supercomputer in May 2014
manufactured by D-Wave. Dubbed the "D-Wave Two", this computer
boasts of having 512 "qubits" per chip and is supposedly 11,000 times
faster than Intel's fastest chip, at least on some tasks. Although at first

glance it seems like a strange investment, but the supercomputer is a
hardware that is perfectly suited for the type of data crunching tasks that
Google needs in its business, particularly in search and automation.
D-Wave’s flagship product, the 512-qubit D-Wave Two quantum computer,
is the most advanced quantum computer in the world. It is based on a
novel type of superconducting processor that uses quantum mechanics to
massively accelerate computation.
In early 2014, it was reported, based on documents provided by former
NSA contractor Edward Snowden, that the U.S. National Security Agency
(NSA) is running a $79.7 million research program (titled "Penetrating Hard
Targets") to develop a quantum computer capable of breaking vulnerable
encryption.
Applications of Quantum Computing
The various applications of quantum computing are:
Quantum Parallelism
In classical computers, parallel computing is performed by having several
processors linked together. In a quantum computer, a single quantum

processor is able to perform multiple computations on its own. Parallelism
allows a quantum computer to work on many computation at once.
Quantum Simulation
Simulation of quantum systems has been said to be a "holy grail" of
quantum computing: it will allow us to study, in remarkable detail, the
interactions between atoms and molecules.
High Speed Computation
Another of the many tasks for which the quantum computer is inherently
faster than a classical computeris at searching through a space of potential
solutions for the best solution. Researchers are constantly working on new
quantum algorithms and applications.
Database Search
Another use of quantum computers is searching huge amounts of data. For
a phone book with one million phone numbers, it could take one million
steps. In 1996, Lov Grover from Bell Labs discovered that a quantum
computer would be able to do the same task with one thousand steps
instead of one million.

Cryptography
There is no reason to worry — classical cryptography is not completely
jeopardized. Although certain aspects of classical cryptography would be
jeopardized by quantum computing, quantum mechanics also allows for a
new type of highly secure cryptography.
Optimization
Imagine you are building a house, and have a list of things you want to
have in your house, but you can’t afford everything on your list because
you are constrained by a budget. What you really want to work out is the
combination of items which gives you the bestvalue for your money. This is
an example of an optimization problem, where you are trying to find the
best combination of things given some constraints. Typically, these are
very hard problems to solve because of the huge number of possible
combinations. Optimization principles can be used for:
Water Network Optimization
Radiotherapy Optimization

Protein Folding
Machine Learning
When you look at a photograph it is very easy for you to pick out the
different objects in the image: Trees, Mountains, Velociraptors etc. This
task is almost effortless for humans, but is in fact a hugely difficult task for
computers to achieve. This is because programmers don’t know how to
define the essence of a ‘Tree’ in computer code. Machine learning is the
most successful approach to solving this problem, by which programmers
write algorithms that automatically learn to recognize the ‘essences’ of
objects by detecting recurring patterns in huge amounts of data.
Monte Carlo Simulation
Many things in the world are uncertain, and governed by the rules of
probability. Monte Carlo simulation, which relies on repeated random
sampling to approximate the probability of certain outcomes, is an
approach used in many industries such as finance, energy, manufacturing,
engineering oil & gas and the environment. For a complex model, with

many different variables, this is a difficult task to do quickly, and quantum
computing can be applied to get answers
Future Scope
The technology of quantum computing could herald radical changes for the
following areas, to name a few:
1. Lockheed Martin plans to use its D-Wave to test jet software that is
currently too complex for classical computers leading to safer airplanes.
2. Quantum computers will be able to analyze the vast amount of data
collected by telescopes and seek out Earth-like planets.
3. Campaigners will comb through reams of marketing information to best
exploit individual voter preferences in order to win elections.
4. Hyper-personalized advertising, based on quantum computation, will
stimulate consumer spending to Boost GDP.

5. Computational models will help determine how diseases develop inorder
to detect cancer earlier.
6. Google is using a quantum computer to design software that can
distinguish cars from landmarks in order to develop auto-drive.
7. Precision forecasting will give people more time to take cover so as to
reduce weather-related deaths.
8. Sophisticated analysis of traffic patterns in the air and on the ground will
forestall bottlenecks and snarls and help travelers cut back on travel time.
9. By mapping amino acids,for example, or analyzing DNA-sequencing
data, doctors will discover and design superior drug-based treatments.
Analysis
Quantum computing is without doubt one of the hottest topics at the current
frontiers of computing or even of the whole science. It sounds very
attractive and looks very promising.

At present, quantum computers and quantum information technology
remains in its pioneering stage. At this very moment obstacles are being
surmounted that will provide the knowledge needed to thrust quantum
computers up to their rightful position as the fastest computational
machines in existence. Error correction has made promising progress to
date, nearing a point now where we may have the tools required to build a
computer robust enough to adequately withstand the effects of
decoherence. Quantum hardware, on the other hand, remains an
emerging field, but the work done thus far suggests that it will only be a
matter time before we have devices large enough to test Shor's and other
quantum algorithms. Thereby, quantum computers will emerge as the
superior computational devices at the very least, and perhaps one day
make today's modern computer obsolete.
So the question arises, when will there be a real quantum computer?
It depends on your definition. There are quantum computers already, but
not of sufficient power to replace classical computers. D-Wave
technologies has already made concrete steps in the right direction but
they are yet to establish the authenticity of their work which will be
recognized by all stake holders. While practical quantum technologies are
already emerging — including highly effective sensors, actuators and other

devices — a true quantum computer that outperforms a classical computer
is still years away. Theorists are continually figuring out better ways to
overcome decoherence, while experimentalists are gaining more and more
control over the quantum world through various technologies and
instruments. Scientists have struggled to entangle more than a handful of
qubits, and to maintain them in their quantum state. Lab devices sufferfrom
drop-out, where the qubits lose their ambiguity and become straightforward
1s and 0s. This has ensured that quantum computers remain confined to
the lab - proofs of principle capable of solving only elementary problems.
The pioneering work being done today is paving the way for the coming
quantum era.
Conclusion
Quantum computation has its origins in highly specialized fields of
theoretical physics, but its future undoubtedly lies in the profound effect it
will have on the lives of all mankind. Neils Bohr, the Danish Physicist who
postulated the Bohr’s Model once stated that "If quantum mechanics hasn't
profoundly shocked you, you haven't understood it yet." Gentlemen, the
quantum revolution is already under way, and the possibilities that lie
ahead are limitless. I would conclude my presentation by stating that “It is

actually possible to find a needle in a haystack using quantum
computation”.
I thank you all for a patient hearing. The house is now open for queries …..

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