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STREAM: ELECTRONICS & COMMUNICATION TOPIC: PRESENTED BY : Sweety Jain ( 6th EC) Ph no : (079) 27573665 Emailid: [email protected] Tansi Modi (6th EC) Ph no : (02742) 255300 [email protected] 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.