Advances in quantum teleportation

Abstract

Quantum teleportation is one of the most important protocols in quantum information. By exploiting the physical resource of entanglement, quantum teleportation serves as a key primitive in a variety of quantum information tasks and represents an important building block for quantum technologies, with a pivotal role in the continuing progress of quantum communication, quantum computing and quantum networks. Here we review the basic theoretical ideas behind quantum teleportation and its variant protocols. We focus on the main experiments, together with the technical advantages and disadvantages associated with the use of the various technologies, from photonic qubits and optical modes to atomic ensembles, trapped atoms, and solid-state systems. Analysing the current state-of-the-art, wefinish by discussing open issues, challenges and potential future implementations. From Science Fiction to RealityIt has been over two decades since the discovery of quantum teleportation, in what is arguably one of the most interesting and exciting implications of the 'weirdness' of quantum mechanics. Previous to this landmark discovery, this fascinating idea belonged to the realm of science fiction. First coined in a 1931 book by Charles H. Fort 1 , the term teleportation has since been used to refer to the process by which bodies and objects are transferred from one location to another, without actually making the journey along the way. Since then it has become a fixture of pop culture, perhaps best exemplified by Star Trek's celebrated catchphrase "Beam me up, Scotty."In 1993, a seminal paper 2 described a quantum information protocol, dubbed quantum teleportation, that shares several of the above features. In this protocol, an unknown quantum state of a physical system is measured and subsequently reconstructed or 'reassembled' at a remote location (the physical constituents of the original system remain at the sending location). This process requires classical communication and excludes superluminal communication. Most importantly, it requires the resource of quantum entanglement 3,4 . Indeed, quantum teleportation can be seen as the protocol in quantum information that most clearly demonstrates the character of quantum entanglement as a resource: Without its presence, such a quantum state transfer would not be possible within the laws of quantum mechanics.Quantum teleportation plays an active role in the progress of quantum information science [5][6][7][8] . On the one hand it is a conceptual protocol crucial in the development of formal quantum information theory, on the other it represents a fundamental ingredient to the development of many quantum technologies. Schemes such as quantum repeaters 9 -pivotal for quantum communication over large distances -quantum gate teleportation 10 , measurement-based computing 11 , and port-based teleportation 12 all derive from the basic scheme. The vision of a quantum network 13 draws inspiration from it. Teleportation has also been used as a simple tool for exploring 'extreme' physics,...

General bounds for sender-receiver capacities in multipoint quantum communications

“…The most typical communication tasks are quantum key distribution (QKD) [7][8][9][10][11][12][13][14][15][16][17], reliable transmission of quantum information [18,19] and distribution of entanglement [20][21][22]. The latter allows two remote parties to implement powerful protocols such as quantum teleportation [23][24][25], which is a crucial tool for the contruction of a future quantum Internet [26,27]. Unfortunately, practical implementations are affected by decoherence [28].…”

“…The latter result completely characterizes the fundamental rate-loss scaling that affects any point-to-point protocol of QKD through a lossy communication line, such as an optical fiber or free-space link. The novel and general methodology that led to these results is based on a suitable combination of quantum teleportation [23][24][25] with a LOCC-monotonic functional, such as the relative entropy of entanglement (REE) [33][34][35]. Thanks to this combination, Ref.…”

Quantum Teleportation Between Discrete and Continuous Encodings of an Optical Qubit

“…For example, using hybrid methods in quantum computing [5] and error correction [6] is favorable, compared to the mainstream CV and DV protocols, in terms of the number of resources required. Long-distance distribution of CV entanglement requires hybrid processing to mitigate the effect of propagation losses [7,8].Taking advantage of these protocols however requires a procedure for transferring quantum data between continuous and discrete qubit systems [4,9]; hybrid teleportation is therefore identified as one of the three key priorities for quantum teleportation science [10]. In this work we make a step towards this goal, demonstrating quantum teleportation by means of a hybrid entangled channel.…”

Quantum light

“…Quantum teleportation (see [8] for a recent review article), proposed in 1993 and first experimentally demonstrated at the Universities of Rome and Innsbruck in 1997, allows the flawless transfer of a property between two quantum particles -e.g., two photons -without running into a contradiction with the no-cloning theorem. As explained in Figure 2a, it requires three particles - one FIG.…”