QuantumTeleportation

Biswajit PratihariElectrical Engg.,7th

Semester 0901106264

Guided by:Dr. Abhimanyu MohapatraDr. Ranjan Kumar Jena

Outline of the Talk

Introduction Need for Teleportation The Beginning.. Failures and further Advancements How feasible is Teleportation .?? Remarkable Achievements Application in Real World Advantages of QT References

What Teleportation is..??

Quantum teleportation, or entanglement-assisted teleportation, is a process by which a qubit (the basic unit of quantum information) can be transmitted exactly from one location to another, without the qubit being transmitted through the intervening space. It includes making an object disintegrate in one place while a perfect replica appears somewhere else.

Various forms of transportation require us to cross a physical distance, which can take anywhere from minutes to many hours.

Telecommunication+

Transportation=

Teleportation

Need for Teleportation

How does all these start.??In 1993, the idea of teleportation

moved out of the realm of science fiction and into the world of theoretical possibility. The idea was first expounded by Charles Bennett and his co-workers from IBM. They confirmed that quantum teleportation was possible, but only if the original object being teleported was destroyed.

The procedure for teleportation in science fiction varies from story to story but generally goes as follows: A device scans the original object to extract all the information needed to describe it. A transmitter sends the information to the receiving station to obtain an exact replica of the original.

Why did they fail.?? It violated the Heisenberg’s Uncertainty

Principle, according to which one can’t perform a perfect scan of the object to be teleported. Because the more accurately an object is scanned, the more it is disturbed by the scanning process, until one reaches a point where the object’s original state has been completely disturbed, still without having extracted enough information to make a perfect exact replica.

The location or velocity of every atom and electron would be subjected to errors.

The law makes it impossible to measure the exact quantum state of any object with certainty.Therefore, it would seem that a perfect copy

cannot be made.

But if you can’t know the position of particle, then how can you teleport it?

OrIf one can’t extract enough information from an object to make a perfect replica, it would seen that a perfect copy can’t be made.

In 1998, physicists at the California Institute of Technology (CalTech), along with two European groups, turned the IBM ideas into reality by successfully teleporting a photon, a particle of energy that carries light, using a phenomenon known as ENTANGLEMENT or EINSTEIN-PODOLSKY-ROSEN (EPR) EFFECT.

Entanglement Or EPR Effect

The existence of an “entangled state” was suggested in an experiment by the 3 scientists in 1935.

It states that when two particles come into contact with one another, they can become “entangled".In an entangled state, both particles remain part of the same quantum system so that whatever you do to one of them affects the other one in a predictable way. Thus, it shows how, in principle, entangled particles might serve as "transporters" of sort.

ENTANGLED PHOTON PAIRS are created when a laser beam passes through a crystal such as beta barium borate. It converts a single photon into two photons of lower energy, one polarized vertically (on red cone), one polarized horizontally (on blue cone). If the photons happen to travel along the cone intersections (green), neither photon has a definite polarization, but their relative polarizations are complementary i.e. they are then entangled.

The process behind EntanglementIn entanglement, at least 3 photons are needed to achieve quantum teleportationPhoton A: The photon to be teleportedPhoton B: The transporting photonPhoton C: The photon that is entangled with photon B

If researchers tried to look too closely at photon A without entanglement, they would bump it, and thereby change it. By entangling photon B and C, researchers can extract some information about photon A, and the remaining information would be passed on to B by way of entanglement, and then on to photon C. When researchers apply the information from photon A to photon C, they can create an exact replica of photon A. However, photon A no longer exists as it did before the information was sent to photon C.

How hard is it to teleport an atom?

Photons have very few pairs of parameters: color, duration,amplitude, phase, polarization, beam size. That’s about it.

While atoms have a lot more (about 100 different pairs).

Recent discoveries have led to the teleportation of photons. So, with further development intechnology, it wouldn’t be tough enoughto teleport the atom in near future.

How hard is it to teleport a living being?

To date there are a few science experiments that hascreated life. The smallest living organism are viroid. Some areas small as 10,000 atoms.

We have teleported only one pair of information.

Teleporting a viroid is 100*10,000 times (106 times)harder=roughly a milliontimes harder.

How hard is it to teleport a human?

There is about 1027 atoms in a person.With 100 parameter pairs per atom,

that’s about 1029 pair ofinformation. So far we have done only 1 pair, so a human isabout 1029 times harder.

For a person to be transported, amachine would have to be built that canpinpoint and analyse all of the 1027

atoms that make up the human body.

Some Success Stories.

In 2002, some researchers at the Australian National University successfully teleported a laser beam.

In 2004, researchers from the University of Vienna and the Austrian Academy of Science teleported particles of light over a distance of 600m using Optical Fibre.

In Oct 4,2006, at the Neil Bohr’s Institute, Denmark, Dr. Polzik and his team teleported information stored in a laser beam into a cloud of atom across 1.6 feet. It involves teleportation between light and matter, two different objects.

And they continued..

In May 2010, a team of 15 Chinese researchers from Tsinghua University in Beijing and the Hefei National Laboratory achieved secure quantum-key distribution over 16 kilometres of free-space.

In April 2011, physicist at University of Tokyo, teleported a complex set of quantum information from one point to another.

In May 2012, an international research team including several scientists from the University of Waterloo has achieved quantum teleportation over a record-breaking distance of 143 kilometres through free-space between the two Canary Islands of La Palma and Tenerife off the Atlantic coast of North Africa.

Application in Real WorldQuantum Cryptography Quantum cryptography allows the transmission of information with 100% security ensured by the law of physics. Potential application for commerce and military purpose.Quantum Computation Moore’s law predicts that computer double its speed, memory performance, etc. every 18 months. But the size and weight of computers remain the same.This means more and more is expected from fewer

and fewer atoms. Eventually, classical physics will no longer valid. A new way of computing will be required.

Present Tech- TELEPRESENCE

Telepresence system is unique and has been designed to enable a life-size image of a person to appear within a 3D environment.You can :- Make eye contact with individuals Use props Hold true two-way conversations - communicating naturally with anyone or any group of people anywhere in the world.× The only thing you can't do is shake hand.

Tata Communication began public-room service in India in July 2008 and currently has 30 public Telepresence rooms live globally. These rooms can be reserved by anyone for a pay-per use hourly rate, typically in the $500/hour range. They are accessible 24*7 and are proven as a cost-effective method for enabling higher quality collaboration across geographies.

Major manufactures, commercial companies and defence establishments of Telepresence equipment are; Cisco, Polycom, Tandberg, HP Halo (Hewlett-Packard), IBM and Lifesize.

Telepresence systems are recently employed educational institutes like in Oxford University and National Institute of Science & Technology (USA).

Advantages

Transmission at higher rates. Secure data transmission. Can detect eavesdropping. Transportation becomes much

easier. Reduced cost of transportation. Accidents will be completely

absent. Faster transportation.

References ht tp : / /www. research . ibm.com

ht tp : / /www.e lec t ron i csnews .com.au

ht tp : / / en .w ik iped ia .o rg

ht tp : / /www.youtube .com

ht tp : / /www.wi red . com

Entanglement and Quantum Teleportation by Stephen Bartlett

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