scholarly journals Twenty Years of Quantum State Teleportation at the Sapienza University in Rome

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 768 ◽  
Author(s):  
Francesco De De Martini ◽  
Fabio Sciarrino

Quantum teleportation is one of the most striking consequence of quantum mechanics and is defined as the transmission and reconstruction of an unknown quantum state over arbitrary distances. This concept was introduced for the first time in 1993 by Charles Bennett and coworkers, it has then been experimentally demonstrated by several groups under different conditions of distance, amount of particles and even with feed forward. After 20 years from its first realization, this contribution reviews the experimental implementations realized at the Quantum Optics Group of the University of Rome La Sapienza.

2017 ◽  
Vol 95 (5) ◽  
pp. 498-503
Author(s):  
Syed Tahir Amin ◽  
Aeysha Khalique

We present our model to teleport an unknown quantum state using entanglement between two distant parties. Our model takes into account experimental limitations due to contribution of multi-photon pair production of parametric down conversion source, inefficiency, dark counts of detectors, and channel losses. We use a linear optics setup for quantum teleportation of an unknown quantum state by the sender performing a Bell state measurement. 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 experimental results.


2018 ◽  
Vol 4 (10) ◽  
pp. eaas9401 ◽  
Author(s):  
Meiru Huo ◽  
Jiliang Qin ◽  
Jialin Cheng ◽  
Zhihui Yan ◽  
Zhongzhong Qin ◽  
...  

Quantum teleportation, which is the transfer of an unknown quantum state from one station to another over a certain distance with the help of nonlocal entanglement shared by a sender and a receiver, has been widely used as a fundamental element in quantum communication and quantum computation. Optical fibers are crucial information channels, but teleportation of continuous variable optical modes through fibers has not been realized so far. Here, we experimentally demonstrate deterministic quantum teleportation of an optical coherent state through fiber channels. Two sub-modes of an Einstein-Podolsky-Rosen entangled state are distributed to a sender and a receiver through a 3.0-km fiber, which acts as a quantum resource. The deterministic teleportation of optical modes over a fiber channel of 6.0 km is realized. A fidelity of 0.62 ± 0.03 is achieved for the retrieved quantum state, which breaks through the classical limit of1/2. Our work provides a feasible scheme to implement deterministic quantum teleportation in communication networks.


2006 ◽  
Vol 13 (04) ◽  
pp. 403-413 ◽  
Author(s):  
Thomas Durt

We study different techniques that allow us to gain complete knowledge about an unknown quantum state, e.g. to perform full tomography of this state. In a first time, we focus on two simple cases, full tomography of one- and two-qubit systems. We analyze and compare those techniques according to two criteria. Our first criterion is the minimisation of the redundancy of the data acquired during the tomographic process. In the case of two-qubits tomography, we also analyze this process from the point of view of factorisability, so to say we analyze the possibility to realise the tomographic process through local operations and classical communications between local observers. Finally, we present new results that concern the extension of the one- and two-qubit cases to higher dimensions.


2005 ◽  
Vol 83 (7) ◽  
pp. 687-698
Author(s):  
F M Toyama ◽  
K Saito

We present a time-dependent model for teleportation of an unknown quantum state of position and momentum. With this model, we analyze a situation in which Bob (receiver) is ignorant of the Hamiltonian that describes the time-evolution of a post-measurement state generated at Bob's site. We illustrate that the time-evolution of the post-measurement state deteriorates the fidelity of the quantum teleportation. We also illustrate a special situation in which a two-mode input state is transformed into a one-mode state by the teleportation. In addition, we discuss an optimal situation in which a high teleportation probability and a high degree of teleportation fidelity can be achieved.PACS Nos.: 03.65.–w, 03.67.Hk


2016 ◽  
Vol 23 (04) ◽  
pp. 1650018 ◽  
Author(s):  
Paweł Caban ◽  
Andrzej Molenda ◽  
Kamila Trzcińska

The fact that several copies of a local quantum state — when processed together — can generate a nonlocal correlation, i.e. the superactivation of quantum nonlocality, is a well-known feature of quantum mechanics. Most of research results focused strongly on the bipartite scenario. In this paper we show that the activation of violation of Svetlichny inequality, reported for the first time in our previous paper, is not an exceptional phenomenon but holds for a broad class of quantum states as well for pure as for mixed, noisy ones.


2013 ◽  
Vol 40 (2) ◽  
pp. 244-256 ◽  
Author(s):  
Holger Funk

In the history of botany, Adam Zalužanský (d. 1613), a Bohemian physician, apothecary, botanist and professor at the University of Prague, is a little-known personality. Linnaeus's first biographers, for example, only knew Zalužanský from hearsay and suspected he was a native of Poland. This ignorance still pervades botanical history. Zalužanský is mentioned only peripherally or not at all. As late as the nineteenth century, a researcher would be unaware that Zalužanský’s main work Methodi herbariae libri tres actually existed in two editions from two different publishers (1592, Prague; 1604, Frankfurt). This paper introduces the life and work of Zalužanský. Special attention is paid to the chapter “De sexu plantarum” of Zalužanský’s Methodus, in which, more than one hundred years before the well-known De sexu plantarum epistola of R. J. Camerarius, the sexuality of plants is suggested. Additionally, for the first time, an English translation of Zalužanský’s chapter on plant sexuality is provided.


2012 ◽  
Vol 41 (3) ◽  
pp. 16-21
Author(s):  
Tony Burke

Scholars interested in the Christian Apocrypha (CA) typically appeal to CA collections when in need of primary sources. But many of these collections limit themselves to material believed to have been written within the first to fourth centuries CE. As a result a large amount of non-canonical Christian texts important for the study of ancient and medieval Christianity have been neglected. The More Christian Apocrypha Project will address this neglect by providing a collection of new editions (some for the first time) of these texts for English readers. The project is inspired by the More Old Testament Pseudepigrapha Project headed by Richard Bauckham and Jim Davila from the University of Edinburgh. Like the MOTP, the MCAP is envisioned as a supplement to an earlier collection of texts—in this case J. K. Elliott’s The Apocryphal New Testament (Oxford 1991), the most recent English-language CA collection (but now almost two decades old). The texts to be included are either absent in Elliott or require significant revision. Many of the texts have scarcely been examined in over a century and are in dire need of new examination. One of the goals of the project is to spotlight the abilities and achievements of English (i.e., British and North American) scholars of the CA, so that English readers have access to material that has achieved some exposure in French, German, and Italian collections.


Author(s):  
David Willetts

Universities have a crucial role in the modern world. In England, entrance to universities is by nation-wide competition which means English universities have an exceptional influence on schools--a striking theme of the book. This important book first investigates the university as an institution and then tracks the individual on their journey to and through university. In A University Education, David Willetts presents a compelling case for the ongoing importance of the university, both as one of the great institutions of modern society and as a transformational experience for the individual. The book also makes illuminating comparisons with higher education in other countries, especially the US and Germany. Drawing on his experience as UK Minister for Universities and Science from 2010 to 2014, the author offers a powerful account of the value of higher education and the case for more expansion. He covers controversial issues in which he was involved from access for disadvantaged students to the introduction of L9,000 fees. The final section addresses some of the big questions for the future, such as the the relationship between universities and business, especially in promoting innovation.. He argues that the two great contemporary trends of globalisation and technological innovation will both change the university significantly. This is an authoritative account of English universities setting them for the first time in their new legal and regulatory framework.


Sign in / Sign up

Export Citation Format

Share Document