Quantum computing is the computing which uses the laws of quantum mechanics to process information. Quantum computer works on qubits, which stands for "Quantum Bits". With quantum computers, factoring of prime numbers are possible.

1. “quantum computing”
By shivangi gupta

2. Overview
Introduction
Qubit.
How to write and read a Qubit.
Superposition
Double Slit experiment.
Schrodinger’s Cat experiment.
Quantum Entanglement
 Applications

3. Introduction
 Quantum computing is the computing which uses
the laws of quantum mechanics to process
information.
 Quantum mechanics deals with motion and
interaction of subatomic particles. Eg, atom,
electrons.
 Quantum computer works on qubits, which stands
for "Quantum Bits".

4. QUBIT
Qubit is similar to a bit in classical computers.
They store
-0
-1
-0 and 1 both.
 Qubits are made with Sub atomic particles .

5. How electrons can be used to store data?
Electron is a charged particle
When a charged particle move they create a
magnetic field.
So electron behaves like a magnet. It has 2
states
Spin up.
Spin down.

6. Taking 2 electrons to make Qubit.
=
=
=
=
11
01
10
11

7.  Firstly, we apply a strong magnetic field , electron comes in SPIN DOWN
position.
 Spin Up – 1
Spin Down -0
 Now for writing “1” , we apply a microwave of specific frequency , and let the
electron come in SPIN UP.
 For 0, it is already in SPIN DOWN.
How To Write a Qubit.

8. How To Read a Qubit.
 If the electron stores “1” , then if we remove the microwave
then a photon of particular wavelength is emitted, and
electron comes in low energy states.
 And in case of “0” nothing is emited.

9. 2 important behaviours of electron
Quantum Superposition.
Quantum Entanglement.

10. Superposition
 The principle of Superposition states that “while we
do not know what the state of any electron is, it is
actually in all possible states simultaneously, as long
as we don't look to check”.

11. Superposition of Single elctron’s states

12. Superposition of 2 electron’s states

13. Schrodinger’s Cat experiment
 To illustrate this theory, we can use the famous analogy of Schrodinger's
Cat.
 First, we have a living cat and place it in a thick lead box.
 We then throw in a vial of cyanide and seal the box. We do not know if
the cat is alive
if the cyanide capsule has broken
the cat has died.
 Since we do not know, the cat is both dead and alive
 According to quantum law –It is in a superposition of states.
 “It is only when we break open the box and see what condition the cat is
then only the superposition is lost, and the cat must be either alive or
dead.”

14.  Cat is closed in a closed box .

15. Double slit experiment
 On the left, we have a gun that can fire bullets
 The bullets will be fired at a wall that has two slits.
 Behind the wall with two slits, is a wall that will measure the number of bullets that
got through the wall and where they landed.
 The graph behind this wall will display the probability distribution for where the
bullets hit.
 First, we’ll leave the bottom slit open. The distribution is normal.
 When we leave the top slit open, the distribution is once again normal.
 When both slits are left open, the distribution is simply the sum of the two previous
distributions. This tells us that the bullets go though one slit or the other.

16. Particles

17. Interference of water waves
Wave

19. Superposition of waves

20. Interference of electrons
Electron

21. Interference of electrons
Which slit
does an
electron
pass
through ?
It passes
through
both the
slits at the
same time.

22. Why electron shows this behaviour?
Electron acts like “particles
as well as wave”.

23. The double slit experiment
Interference of electrons
But when
we observe
then then it
starts
behaving
like a
particle.

24. What are the conclusions?
When we “observe” the electron, it “behaves” like
particles.
Electron may exist in 2 positions at the same time.

25. Quantum Entanglement
 When electron start interacting with each other , then they
start behaving in a coupled manner.
 Here coupling means electron cannot represent the
information individually, but if we read them together in some
particular manner then we will get the information.

27.  2 qubit 22 =4 bit
 4 qubit 24 =16 bit
 300 qubit 2300 bit
2300 is the no of particles present in this Universe

28. Application 1
all paths one by one and find which is optimum.
But Quantum Computer traverse all paths at same time and this is how our quantum
computer does computation on TSP.
Traverse gives output which is optimum.
Travelling Sales Man Problem.

29. Application 2
How much time would a human take to find out the prime factors of this number.
1273618273681872649884029823850438598734989857938659385764872547624341294298402197498213749823409824098209850298502840923
9048029402049820420752746265371246524723564782349273509283508230580298509860398604099749608798347598307509385730457630583
7503560356038653087456230875602385763857360857630567302097568107581275821753680736508273560319876518765817582654187568207
5627569726027651826581725892548721548756295690265923765107561298765120875618756108756180275680172568017566108286734987529
0587239857239857239057293085716128748245625465214876254982715687235263046539728721648192764182764812746821746127648217648
2764827685976589374658746812746827468217468927567254794368174683274618746812734612987546574765247821461821276081201640812
7460213876408756847568736428376421807462876421708406827649204789234798247928479821479826508765834765082768017468327461802
7461023746120983472190847219847120749218759084375029387529387591837598327459834759823745983274598234759238465901647865832
4705623076523487563842765832407560238745618037562873419872984723984792817498127498759823406509837456087345068734568327458
9749827492837409281374982576834756875421655646547826487126489127468721648724687216487248672164897234687264872468172648712
6487236481726487256823475682347562837658397652839765283475623487562394875624387568273456298376528375682375682376582375628
3568327652353576235763485763284756837658376587356873658736587325687345683756837658375683756873658723568735672576235872365
8723658723658723658723658762358723658768235739487592387598234759803759823475983427598347598375983427598732454873658723648
2736482164821468273468217468724687246827143681274682734682376283946239842394628374682137648237468274687123468172346812736
4827346827436888
Human would take time that would equal to the life time of Galaxy. But Quantum
Computer would take about 30 Seconds.

30. Application 3
 RSA encryption will not be safe in Quantum World.
 This is because , RSA algorithm is based on prime
factors. It computes n=pq, where p and q are prime
numbers.
 Quantum Computers can solve them in Seconds.

31. Application 4
 Developing a new drug is a complicated process.
 Chemists have to test tons of different molecular
combinations to find one that actually has properties that are
effective against a disease.
 This process can take years and cost millions of dollars.
Chemists bring tons of these combinations to later-stage trials
and many of them still end up failing.
 A quantum computer would be able to map out trillions of
molecular combinations and quickly identify the ones
that would most likely work, significantly cutting down
the cost and the time of drug development.

32. Application 5
Accelerating space exploration
 Astronomers have discovered nearly 2,000 confirmed planets
outside our solar system using the Kepler space telescope.
 The Kepler search involves peering at these distant so-called
exoplanets and waiting for them to pass in front of their host star.
 When that happens, the exoplanets cast a shadow that
astronomers can then analyze and make predictions about whether
their atmosphere is suitable for life or not.
 A quantum computer could tackle more data in any given telescope
view, spot more exoplanets, and help quickly identify which ones
have the most potential to harbor life. It could even uncover
exoplanets that Kepler missed during its first run through older
images.

33. Thank You
