An Introduction to Quantum Teleportation

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1998

Quantum teleportation-the transmission and reconstruction over arbitrary distances of the state of a quantum system-is demonstrated experimentally. During teleportation, an initial photon which carries the polarization that is to be transferred and one of a pair of entangled photons are subjected to a measurement such that the second photon of the entangled pair acquires the polarization of the initial photon. This latter photon can be arbitrarily far away from the initial one. Quantum teleportation will be a critical ingredient for quantum computation networks.

Alhun Aydın, 2010

Teleportation is usually seen as a science-fiction term. In spite of that, the possibility of teleportation within the range of physics laws, has been being studied since its discovery in 1993. We examine the teleportation that is done with using quantum entanglement, and we explore quantum teleportation both theoretically and experimentally, with also giving fundamental background knowledge of the process. Furthermore we discuss the philosophy of some weird quantum phenomena with regard to quantum teleportation.

Nature, 2006

Quantum teleportation 1 is an important ingredient in distributed quantum networks 2 , and can also serve as an elementary operation in quantum computers 3 . Teleportation was first demonstrated as a transfer of a quantum state of light onto another light beam 4-6 ; later developments used optical relays 7 and demonstrated entanglement swapping for continuous variables 8 . The teleportation of a quantum state between two single material particles (trapped ions) has now also been achieved 9,10 . Here we demonstrate teleportation between objects of a different nature-light and matter, which respectively represent 'flying' and 'stationary' media. A quantum state encoded in a light pulse is teleported onto a macroscopic object (an atomic ensemble containing 10 12 caesium atoms). Deterministic teleportation is achieved for sets of coherent states with mean photon number (n) up to a few hundred. The fidelities are 0.58±0.02 for n=20 and 0.60±0.02 for n=5higher than any classical state transfer can possibly achieve 11 . Besides being of fundamental interest, teleportation using a macroscopic atomic ensemble is relevant for the practical implementation of a quantum repeater 2 . An important factor for the implementation of quantum networks is the teleportation distance between transmitter and receiver; this is 0.5 metres in the present experiment. As our experiment uses propagating light to achieve the entanglement of light and atoms required for teleportation, the present approach should be scalable to longer distances. Quantum teleportation-a disembodied transfer of a quantum state with the help of distributed entanglement-was proposed in a seminal paper 1 . The generic protocol of quantum teleportation begins with the creation of a pair of entangled objects which are shared by two parties, Alice and Bob. This step establishes a quantum link between them. Alice receives an object to be teleported and performs a joint measurement on this atomŝ 4 x x J J N = = , and the transverse projections with minimal quantum uncertainties, x z y J J J 2 1 2 2

We present a short summary of progress achieved at the Center for Engineering Science Advanced Research (CESAR) of the Oak Ridge National Laboratory (ORNL) in the recently initiated Quantum Teleportation project. The primary objective of this effort is to study the signaling potential of quantum information processing systems based on quantum entanglement. Our initial effort has focused on the development and demonstration of a novel, ultra-bright EPR source, based upon the innovative concept of cascaded type-II optical parametric downconversion. The main features of this source are analyzed, and results of a multi-photon entanglement experiment are presented. Theoretical challenges for superluminal communications are also highlighted.

Nature, 2004

Physical Review A, 2000

We consider the teleportation of entangled two-particle and multiparticle states and present a scheme for the teleportation that may be suitable for both entangled atomic states or field states inside high-Q cavities.

2011

This paper contains an overview of the concept of photon entanglement and discusses generating EPR photon pairs and performing Bell state measurements on them. The procedure of quantum teleportation, or transferring the quantum state of a particle onto another particle, is described in detail. The experimental progress in performing such operations is reviewed in relationship to the developing field of quantum communication.

In this paper I have investigated what quantum teleportation is and its implications in the creation of the quantum internet. The paper begins with a broad description of quantum mechanics and the fascinating concepts of superposition of states and quantum entanglement, and how they are fundamental to quantum teleportation. Quantum teleportation is an intriguing consequence of quantum entanglement and superposition states of qubits. It is the technique of transmitting one qubit's state to another qubit, at a completely different location, without physically transporting the qubit. Taking the classic example of Alice and Bob the whole procedure of quantum teleportation is explained. The paper also focuses on the possibility of a quantum internet using the concepts of quantum teleportation and quantum repeaters.It states the advantages of the quantum internet and why it would be a huge leap for mankind. The paper also mentions the use of quantum teleportation to improve quantum cryptography for safer transactions. The conclusions of the paper focus mainly on the hurdles of the creation of the quantum internet such as the decoherence effect.

Quantum teleportation 1 is an important ingredient in distributed quantum networks 2 , and can also serve as an elementary operation in quantum computers 3 . Teleportation was first demonstrated as a transfer of a quantum state of light onto another light beam 4-6 ; later developments used optical relays 7 and demonstrated entanglement swapping for continuous variables 8 . The teleportation of a quantum state between two single material particles (trapped ions) has now also been achieved 9,10 . Here we demonstrate teleportation between objects of a different nature-light and matter, which respectively represent 'flying' and 'stationary' media. A quantum state encoded in a light pulse is teleported onto a macroscopic object (an atomic ensemble containing 10 12 caesium atoms). Deterministic teleportation is achieved for sets of coherent states with mean photon number (n) up to a few hundred. The fidelities are 0.58±0.02 for n=20 and 0.60±0.02 for n=5higher than any classical state transfer can possibly achieve 11 . Besides being of fundamental interest, teleportation using a macroscopic atomic ensemble is relevant for the practical implementation of a quantum repeater 2 . An important factor for the implementation of quantum networks is the teleportation distance between transmitter and receiver; this is 0.5 metres in the present experiment. As our experiment uses propagating light to achieve the entanglement of light and atoms required for teleportation, the present approach should be scalable to longer distances. Quantum teleportation-a disembodied transfer of a quantum state with the help of distributed entanglement-was proposed in a seminal paper 1 . The generic protocol of quantum teleportation begins with the creation of a pair of entangled objects which are shared by two parties, Alice and Bob. This step establishes a quantum link between them. Alice receives an object to be teleported and performs a joint measurement on this atomŝ 4 x x J J N = = , and the transverse projections with minimal quantum uncertainties, x z y J J J 2 1 2 2

Canadian Journal of Physics, 2017

We develop a theory to teleport an unknown quantum state using entanglement between two distant parties. Our theory takes into account experimental limitations due to contribution of multi-photon pair production of parametric down conversion source, inefficiency and dark counts of detectors and channel losses. We use a linear optics setup for quantum teleportation of an unknown quantum state by performing Bell state measurement by the sender. Our theory successfully provides a model for experimentalists to optimize the fidelity by adjusting the experimental parameters. We apply our model to a recent experiment on quantum teleportation and the results obtained by our model are in good agreement with the experiment results.