Download Quantum Teleportation

STREAM: ELECTRONICS & COMMUNICATION
TOPIC:
PRESENTED BY : Sweety Jain ( 6th EC)
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Tansi Modi (6th EC)
Ph no : (02742) 255300
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COLLEGE POSTAL ADDRESS :Shri U.V.Patel College Of Engineering,
Ganpat Vidhyanagar,
Kherva 382 711.
Dist : Mehsana (North Gujarat).
Phone : (02762) 286805.
ABSTRACT
A teleportation machine would be like a fax machine, except that it
would work on 3-dimensional objects as well as documents, it would produce an
exact copy rather than an approximate facsimile, and it would destroy the original in
the process of scanning it. The teleportation technique makes use of quantum
entanglemant. Clouds of trillions of atoms have for the first time being linked by
quantum entanglement that spooky almost telepathic links between distant particles.
A hypothetical method of transportation in which matter or information is
dematerialized, usually instantaneously, at one point and recreated at another. And
Quantum Teleportation is the instantaneous transference of properties from one
quantum system to another without physical contact. Quantum teleportation, in some
sense, can be viewed as splitting up the "quantum" and "information" parts of
quantum information. if you want to move a single atom, then the quantum state
might be crucial, and quantum teleportation can save you a good deal of trouble.The
future applications of teleportation are so immense that almost defy imagination.If
teleportation technologies were to continue into the future, scientists would probably
be able to move past teleporting quantum and begin teleporting matter. Almost any
activity that requires the movement of objects would be incredibly enhanced by
teleportation.Once people see the uses of teleportation in society, they will not want to
stop research until teleportation advancement is exhausted.
AIMS
Our ability to transmit and process information has reached the level where it
can exploit the properties of single quanta. Although such systems are not yet in
commercial use, practical demonstrations have already been made - for example of
quantum cryptography. Devices based on single photons and single electrons are set
to provide a new era in information processing. In addition to their potential
applications, these phenomena continue to provide new ways to probe our
understanding of the world and allow us to explore new physics. This module shows
how the fundamental physics learned in previous core modules on quantum
mechanics, solid-state and statistical physics, can be used as a basis to describe and
explain these new devices. As well as demonstrating the application of physics to
technology, the module also provides helpful grounding for students interested in
careers in the electronics, optoelectronics and photonics industries.
WHAT IS QUANTUM TELEPORTATION ?
Teleportation is the name given by science fiction writers to the feat of making
an object or person disintegrate in one place while a perfect replica appears
somewhere else. How this is accomplished is usually not explained in detail , but the
general idea seems to be that the original object is scanned in such a way as to extract
all the information from it, then this information is transmitted to the receiving
location and used to construct the replica, not necessarily from the actual material of
the original, but perhaps from atoms of the same kinds, arranged in exactly the same
pattern as the original. A teleportation machine would be like a fax machine,
except that it would work on 3-dimensional objects as well as documents, it
would produce an exact copy rather than an approximate facsimile, and it would
destroy the original in the process of scanning it. A few science fiction writers
consider teleporters that preserve the original, and the plot gets complicated when the
original and teleported versions of the same person meet; but the more common kind
of teleporter destroys the original, functioning as a super transportation device, not as
a perfect replicator of souls and bodies.
The teleportation technique makes use of quantum entanglemant. When
particles are fundamentally linked in this way performing operation on one will have
the same effect on the other even if they are physically seperated. Quantum
entanglement is the bizarre property that allows two particles to behave as one, no
matters how far they are, if measure the state of one particle, you instantly determine
the state of the other, this could one day allow us to teleport objects by transferring
their properties instantly from one place to other.
Clouds of trillions of atoms have for the first time being linked by quantum
entanglement that spooky almost telepathic links between distant particles. The feat
opens new possibilities for the quantum communication systems sci-fi-style
teleporting of objects from one place to another. When photons are entangled, the
physical properties of one are instantly linked to the other. In this case the researchers
entangle a pair of photons a then fire a single photon at one of the pair. the resulting
interaction changes the state of both entangled photons effecftively teleporting
quantum bit of information known as qubit from one place to other.
DEFINATION OF TELEPORTATION.
A hypothetical method of transportation in which matter or information is
dematerialized, usually instantaneously, at one point and recreated at another.
Teleportation is the act or process of moving an object or person by psychokinesis.
The term originated with Charles Fort, though he used it to describe magical transport
between Earth and the heavens. Telekinesis is the movement of objects by
scientifically inexplicable means, as by the exercise of an occult power. Psychokinesis
is the production of motion in physical objects by the exercise of psychic or mental
power. And Quantum Teleportation is the instantaneous transference of
properties from one quantum system to another without physical contact.
TELEPORTATION: FROM FICTION TO REALITY
As delineated above, the concept of teleportation in roughly its present
incarnation is only slightly more than a century old. Yet within that century,
teleportation has evolved from the stuff of dime-store fantasy into a feasible
undertaking. Of obvious importance to the development of quantum teleportation was
the emergence of quantum theory in the early twentieth century due to the work of,
among others, Max Planck, Albert Einstein, and Niels Bohr. In 1935 Einstein, along
with Boris Podolsky and Nathan Rosen, published a paper questioning whether the
current theory was adequate to explain all possible observations on the quantum level.
In this so-called EPR Paper, the three scientists basically showed that it was
possible to measure the quantum state of one particle and find that another
particle far away possesses the same state. Thus, they concluded that quantum
theory cannot provide a total description of everything there is to know about a
particle.
The EPR paper was an important beginning because it provided grounds for the
notion that actions performed on one particle can somehow affect its partner even
over great distances. This is known as entanglement and is central to quantum
teleportation.
Within the more definitive realm of "real" science, the latter half of the
twentieth century witnessed a steady march towards the actualization of teleportation.
Following the Einstein-Podolsky-Rosen paper, others continued to pose theories and
experiments refining quantum theory. As a result of this refinement, it became
theoretically possible to teleport a single particle. Finally, in 1997, a group at the
University of Innsbruck in Austria performed the first successful teleportation of the
quantum state of a photon. Thus, in less than one hundred years, quantum
mechanics was born and matured enough such that the once-fantastic idea of
teleportation moved one step closer to reality. The next section will explore in
greater detail the path from early quantum mechanics to practical quantum
teleportation
PREVIOUS BASIC AND PRACTICAL OBJECTIVES
Two research objectives were identified for quantum communication: to
transfer classical information better over noisy channels, and to perform
distributed quantum computing. It is recognized that the practical application of
quantum communication will be driven by how much it can utilize existing
telecommunication technologies. Therefore, the quantum system of choice is clearly
the photon, either via fiber optical communication links or by free space line of sight
optical transmission. Like with quantum communications in general, a key issue to be
resolved concerns how quantum cryptography can be incorporated into existing
telecom systems, using fiber, free space, global satellite, etc.
PHYSICAL INTERPRETATION
Quantum teleportation, in some sense, can be viewed as splitting up the
"quantum" and "information" parts of quantum information. For Alice to
teleport a quantum state to Bob, they must first share a particular type of entangled
quantum state, an EPR pair. That is their "quantum" resource. Then to send her state
to Bob, Alice first measures the state and her EPR pair, getting two classical bits. That
gives her the "information" part, which she can then send to Bob. In the process, the
original quantum state is destroyed, but Bob reconstructs it exactly. The quantum state
has been "teleported" to Bob, even though only classical information passed to him
from Alice In the above circuit, time moves from left to right. The top two lines
represent qubits held by Alice, and the bottom line represents a qubit held by Bob. As
you can see, Alice must make a particular type of measurement called a "Bell
measurement"on her two qubits, and send to Bob the two classical bits that come out
of it. Bob performs the operation P, which depends on the value of the two bits he
receives from Alice .Two particles-particle A and particle B-interact and become
entangled. Particle A is sent to Alice while particle B is sent to Bob1. Meanwhile, the
particle to be teleported-particle C-is sent to alice
as well, so that both particle A and particle C arrive at the same time. Alice mixes
particle A and particle C, which destroys the states of both particles and by
entanglement forces particle B to take on the original characteristics of particle C.
Finally, Alice notifies Bob that the teleportation was successful and that his particle
looks exactly like particle C. Teleportation is complete.
Note that quantum teleportation has very little to do with moving about
large objects: it is simply a way of substituting classical information for quantum
information when we want to move the latter about. A large object like a chair
needs an enormous amount of classical information to describe it completely, but the
exact quantum state of a chair is unlikely to be of any interest. Therefore quantum
teleportation is not going to be useful if you want to move a chair from Los Angeles
to New York. On the other hand, if you want to move a single atom, then the quantum
state might be crucial, and quantum teleportation can save you a good deal of trouble.
PHOTON TRANSMISSION AND DETECTION
Generation of entanglement is but the first step in quantum communication.
Efficient transmission and detection of the photons will preferably be accomplished
through improvements in existing technologies, but the need for quantum error
correction and quantum repeaters was also mentioned.
FUTURE APPLICATIONS
The future applications of teleportation are so immense that almost defy
imagination. Since the beginnings of science fiction people have wondered how
society would change with amazing technologies. However, many uses for
teleportation have not even been thoughtfully considered. Yet, some key applications
can be analyzed to show where society will be headed once teleportation is a reality.
One of the first applications for quantum teleportation would be in
COMMUNICATIONS. Scientists are able to teleport single waves of light and are
attempting angular spins of atoms. By implementing such research into technology,
small bits of quanta can move between two points without moving through the space
between these two points. Furthermore, data can be transferred with this energy and
sent to unique locations that contain a teleportation device at each end. Data is
currently represented in binary as 'off's and 'on's, but with energy it would be
presented as distinct polarizations of photons. Therefore, by sending a photon with a
positive 45-degree spin, people could effectively send a binary 'on'. Teleportation of
energy would thus mean instantaneous communication between two points, since the
time wasted transferring the information is removed. Additionally, data can be sent
twice as fast since each energy transfer contains two bits of data. Instead of two
possible signals, ('off' and 'on'), a quanta can have four states (0, 45, 90, and -45
degrees corresponding to 'on, on', 'on, off', 'off, on', and 'off, off') and thus can send
two 'on' and 'off' states at once. Teleportation would give people unparalleled
communications speed with instantaneous data transfer.
Another interesting use of teleportation in communications is DATA
ENCRYPTION. Since there are four states for sending data with teleportation, a
hacker needs to spend a good deal of time deciphering the code used to produce
the encryption. Since the receiver of the data chooses a new code each time, a hacker
cannot reapply a previous decryption to a message and expect it to work. Thus, the
hacker would encounter innumerable problems trying to decrypt the data and never be
able to receive the information. Additionally, the current theories of teleportation
cause changes to the data if someone receives the information. Thus, "parties at each
end can detect.” The sender of the quantum could realize someone unwanted is
receiving the information if the quanta are changed unexpectedly. Teleportation
would thus provide instantaneous communication as well as secure transactions.
Thus, teleportation would cause much of society to change due to new reliance on
the internet and data transfer.
Nowadays people are being more dependent
on the internet and
telecommunications. Thus, if downloads and data transfers occurred instantly, society
would quickly become based solely on the World Wide Web. The largest complaint
about today's Internet is the slow download times. However, many people would soon
start to send huge files via the Internet if no time was wasted sending the data.
Quantum teleportation is now going to be implemented to form quantum
computers. However, instead of using just one quantum as in teleportation, a
quantum computer requires thousands of quanta. With so many entanglements,
though, the speed of such computers increases such that a quantum computer "could
go exponentially faster than classical computers." Therefore, computer industries
would have to completely change in order to meet the new demand for quicker
machines. People would become undeniably dependent on computers if such fast
machines existed.
If teleportation techno;ogies were to continue into thye future, scientists
would probably be able to move past teleporting quantum and begin teleporting
matter. The first step in teleporting matter would be teleportation of molecules.
Even later in time researchers may be able to teleport inanimate objects.
Although the basis for such technology evades current theory, it is conceivable that it
might eventually be feasible. If this technology were produced, however, society
would totally change. The effects on freight transport would be incredible. There
would be hardly any need to move items by conventional means since everything
would be teleported. Even more incredible is the idea that teleportation devices could
be cheap enough for the common person. Thus, items could be teleported directly
to a person's house or business, eliminating all need for stores or retailers. Just as
online shopping now offers the opportunity to avoid shops, teleportation would mean
instant store-free purchases. Society's total economy would change if teleportation
allowed the transfer of inanimate objects.
There are certainly many more improvements to society if teleportation worked
on inanimate objects. As mentioned before, space exploration would be extremely
enhanced with the ability to teleport machinery to shuttles or space colonies. Also,
teleportation could be used in areas such as warfare. Missiles and bombs could be
instantly placed in enemy locations after a soldier set up a teleportation device behind
enemy lines, thus eliminating any ballistics. Additionally, vehicles could be inserted
into hostile locations through teleportation and then used by present allied soldiers.
Almost any activity that requires the movement of objects would be incredibly
enhanced by teleportation.
Ultimately, research would lead to teleporting animate objects. Just as the
teleportation of inanimate objects is tremendously harder than teleporting elements,
teleporting living creatures is exceedingly harder than teleporting inanimate objects.
There will certainly be many ethical questions involved in this advancement and
research may go slowly. However, the arrival at such teleportation seems inevitable.
Once people see the uses of teleportation in society, they will not want to stop
research until teleportation advancement is exhausted.
ETHICS
As the recent controversy over cloning demonstrates, it is never too early to
consider the moral implications of so-called "science-fiction" technologies. Important
discoveries have a habit of sneaking up on the world, often resulting in a mix of
shock, confusion, and fear.. Simply put, it is never too early to exercise moral
imagination when it comes to research. Quantum teleportation may be in its infancy,
but there is much potential for technologies that could one day pose complex moral
and ethical issues.
For most of the public, the idea of teleportation involves physically moving
an object from one place to another, safely and instantaneously, utilizing some
unexplained advanced technology. In reality, the process is much messier, the key
difference being that in quantum teleportation, the original copy of the teleported
object must be destroyed. For the purposes of discussion, consider a human placed in
a hypothetical teleportation device. His atoms are analyzed, their spin, locations, and
other characteristics passed on to linked particles, and then reconstructed in a far-off
place. Through these processes, however, the original human has been destroyed. This
begs the question, however, of whether teleportation is actually a form of murder.
Unfortunately, the answer to this question is anything but straightforward.
According to quantum theory, the teleported object should be an exact duplicate
of the original, so at least physically the two humans are the same. Yet if this
duplicate is just that, a copy, the original human has not been transported as much
killed and replaced with a imitation. So is the teleported human the same as the
original? It all depends on one's definition of identity. Many religions define a
person's true identity as that of his soul, the spirit that embodies a person during
his lifetime. If a human is teleported, his material body is destroyed and
recreated, exactly as it was, but it is a matter of opinion whether the soul stays
with it. If this is then considered murder, the act is compounded by the fact that some
religions value burying/preserving the body of the deceased, yet through quantum
teleportation, the original body is now disintegrated. On a more basic level, there is
also the question of whether the consciousness of the person teleported would also be
reproduced at the new location. It is still a matter of debate what defines the
consciousness, so there is worry that teleporting a human would create a physically
perfect, yet wholly brain-dead individual at the target location. Less discussed, but
equally important, is what the implications of a successful teleportation would be for
society at large. Namely, successfully transporting a human, body and mind intact,
would imply that a person could be defined by their physical qualities alone. In other
words, their entire personality, beliefs, memories, indeed life, would be merely
the sum of the spins and positions of the subatomic particles composing their
bodies.
Amid all the concerns, it is tempting to dismiss teleportation of living things as
too morally ambiguous to be practical, but there is another side to the issue. Physicist
Roger Penrose points out that humans are constantly destroyed and recreated through
the natural cell cycles in their bodies. One's identity, if it does indeed exist, must
therefore not reside within the cells or tissues of the body, because after all, "We
are each a materially different person from the person we were yesterday". From
this standpoint, quantum teleportation's destruction-recreation process seems almost
natural. Penrose goes on:
And if teleportation is not travelling, then what is the difference in principle
between it and just walking from one room into another ? In the latter case, are not
one’s atom of one moment simply providing the information for the locations of the
atoms of the next moment ? ... There is no significance in preserving the identity of
any particular atom. The question of the identity of any particular atom is not even
meaningful. Does not any moving pattern of atoms simply constitute a kind of wave
of information propagating from one place to another ? Where is the essential
difference between propagation of waves which describes our travellers ambling in a
common place way from one room to the other and that which takes place in the
teleportation device ?
Penrose makes the important point that distinguishing between the identity of a
person as a whole and as a collection of parts (atoms, molecules, etc.) is impossible.
Humans, just like the rest of the physical world, are composed of discrete subatomic
units, units that are neither constant nor unique outside of their explicit combinations
to form matter. Thus, when matter is disassembled and recreated at a remote location
through quantum teleportation, it is essentially experiencing the process of destruction
and recreation that it endures everyday.
Beyond the issues surrounding the mechanics of teleportation are those
stemming from the impact the technology could have on the economy. Millions of
jobs would likely disappear, as the need for long-distance freight would be provided
by a handful of teleportation centers, rather than the extensive shipping network in
place today. Careful consideration would have to be given to how to phase in the
technology without sending the nation into a repression with massive unemployment.
Even further into the future, if teleportation becomes common enough, the entire
consumer-industry infrastructure may have to be overhauled. Goods and services
could be delivered instantaneously to consumers, making today's massive, difficult to
navigate stores obsolete. Once again, the effect on the economy could be astounding,
as millions of store-workers find themselves without a job. In effect, widespread use
of teleportation technologies could completely change how the world shares
resources. The only question is how to manage this change without completely
destabilizing the job market.
HISTORY IN FUTURE
In ancient times, or say in the old mythological stories we used to hear that all
divines, devils and angels can go anywhere within a second where they wish to go.
This can be combined with the idea presented here, that is to teleport the people to the
place where they wish to go. the whole body is replicated at the destination. In history
this was possible with them due to their special powers and now in future this will be
possible with the help of quantum teleportation. thus the idea of being teleported was
already since thousands and thousands of years ago. This miracle of the history will
now be in the future very soon.
SCOPE
Quantum Optics is a highly fertile research field for the future information
technologies. The leading trend of current research is to use quantum mechanical
effects to reach goals that cannot be achieved classically, such as perfectly secure
cryptographic communications, and highly-efficient quantum-parallel computation.
The meeting will cover the main issues of these new fast developing fields. Emphasis
will be given on experimental achievements in the optical domain, and on all
theoretical approaches relevant for quantum information.
On the quantum processing side, attention will be focused on quantum error
correction and fault tolerant quantum computation, and on experimental
implementations of quantum gates using ions, atoms, or cavity QED techniques. On
the quantum communication side, where the driving force is quantum cryptography,
the new related fields of cloning, teleportation, and entanglement purification will be
considered with attention. These topics benefit from the current fast development of
single photon sources, and from the increasingly efficient use of parametric optical
conversion techniques, which are also suited to processing and communication of
quantum continuous variables.
CONCLUSION
The future of teleportation is as varied as the past that led to its creation. Just as
Zeilinger and Braunstein created experiments to make teleportation one step more
plausible, the scientists of tomorrow will strive to make teleportation applicable to
inanimate and even animate materials. Society's fascination with teleportation keeps
the drive for further research strong, ensuring teleportation as an integral part of
society's progress. Science, however, can only go as far as society will allow, making
ethical dilemmas a key issue in the potential uses of teleportation. Although the
advancement of teleportation is irrefutable, the route of such research is unknown and
offers an unpredictable and exciting future.