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L

Posts: 111991
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RE: Quantum entanglement
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Extending Einstein

Researchers at the University of Waterloo and the University of Calgary have carried out an experiment, using the quantum properties of three particles of light, that could provide new insights into the philosophical arguments by Einstein about the foundations of quantum mechanics.
Seventy-seven years after EPR's landmark work, researchers at the Institute for Quantum Computing at the University of Waterloo and at the University of Calgary have experimentally extended the original ideas of Einstein and his colleagues from two to three entangled particles. This new form of three-particle entanglement, based on the position and momentum properties of photons, may prove to be a part of future communications networks that operate on the rules of quantum mechanics and could lead to new fundamental tests of quantum theory that deepen our understanding of the world around us.

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Posts: 111991
Date:
Quantum teleportation
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ESA observatory breaks world quantum teleportation record

An international research team using ESA's Optical Ground Station in the Canary Islands has set a new distance world record in 'quantum teleportation' by reproducing the characteristics of a light particle across 143 km of open air.
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L

Posts: 111991
Date:
RE: Quantum entanglement
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 Quantum Entanglement Can Reach into the Past

Spooky quantum entanglement just got spookier.
Entanglement is a weird state where two particles remain intimately connected, even when separated over vast distances, like two die that must always show the same numbers when rolled. For the first time, scientists have entangled particles after they've been measured and may no longer even exist.
If that sounds baffling, even the researchers agree it's a bit "radical," in a paper reporting the experiment published online April 22 in the journal Nature Physics.

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Ed ~ There is no absolute time frame; there is no universal 'now'.



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L

Posts: 111991
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Title: Cosmological quantum entanglement
Authors: Eduardo Martin-Martinez, Nicolas C. Menicucci

We review recent literature on the connection between quantum entanglement and cosmology, with an emphasis on the context of expanding universes. We discuss recent theoretical results reporting on the production of entanglement in quantum fields due to the expansion of the underlying spacetime. We explore how these results are affected by the statistics of the field (bosonic or fermionic), the type of expansion (de Sitter or asymptotically stationary), and the coupling to spacetime curvature (conformal or minimal). We then consider the extraction of entanglement from a quantum field by coupling to local detectors and how this procedure can be used to distinguish curvature from heating by their entanglement signature. We review the role played by quantum fluctuations in the early universe in nucleating the formation of galaxies and other cosmic structures through their conversion into classical density anisotropies during and after inflation. We report on current literature attempting to account for this transition in a rigorous way and discuss the importance of entanglement and decoherence in this process. We conclude with some prospects for further theoretical and experimental research in this area. These include extensions of current theoretical efforts, possible future observational pursuits, and experimental analogues that emulate these cosmic effects in a laboratory setting.

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Posts: 111991
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Entangled diamonds vibrate together

A pair of diamond crystals has been linked by quantum entanglement. This means that a vibration in the crystals could not be meaningfully assigned to one or other of them: both crystals were simultaneously vibrating and not vibrating.
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Posts: 111991
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Results of entanglement made visible to human eyes.

It's an eye test with a quantum twist: physicists have used humans to detect the results of a quantum phenomenon for the first time.
Nicolas Gisin, a physicist at the University of Geneva in Switzerland, devised a new test to see if the human eye could pick out signs of 'entanglement'.
Gisin and his colleagues were inspired by an experiment carried out in 2008 by Fabio Sciarrino and his team at La Sapienza University in Rome, Italy. Usually, physicists working with entangled photons only deal with a small number at a time. In the Rome experiment, the physicists entangled a pair of photons and then 'amplified' one of them to create a shower of thousands of photons with the same quantum state. In this way, one 'microscopic' photon seemingly became entangled with thousands of others in a 'macroscopic' light field.

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Posts: 111991
Date:
Timelike entanglement
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Title: Extraction of timelike entanglement from the quantum vacuum
Authors: S. Jay Olson, Timothy C. Ralph

Recently, it has been shown that the massless quantum vacuum state contains entanglement between timelike separated regions of spacetime, in addition to the entanglement between the spacelike separated regions usually considered. Here, we show that timelike entanglement can be extracted from the Minkowski vacuum and converted into ordinary entanglement between two inertial, two-state detectors at the same spatial location -- one coupled to the field in the past and the other coupled to the field in the future. The procedure used here demonstrates a clear time correlation as a requirement for extraction, e.g. if the past detector was active at a quarter to 12:00, then the future detector must wait to become active at precisely a quarter past 12:00 in order to achieve entanglement.

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Posts: 111991
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RE: Quantum entanglement
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Entangled En Masse: Physicists Crank Out Billions of Entangled Nucleus-Electron Pairs on Demand

Entanglement, that most counterintuitive quantum phenomenon by which particles share an unseen link that aligns their properties, is looking more mundane all the time. Just last week two groups of researchers reported entangling a photon with a crystal-based device, potentially paving the way for solid-state memories that can store and then release entangled particles as needed.
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Posts: 111991
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The mysterious phenomenon known as quantum entanglement - where objects seemingly communicate at speeds faster than light to instantaneously influence one another, regardless of their distance apart - was famously dismissed by Einstein  as "spooky action at a distance." New experiments could soon answer skeptics by enabling people to see entangled pulses of light with the naked eye.
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Posts: 111991
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Title: Energy-Entanglement Relation for Quantum Energy Teleportation
Authors: Masahiro Hotta

Protocols of quantum energy teleportation (QET), while retaining causality and local energy conservation, enable the transportation of energy from a subsystem of a many-body quantum system to a distant subsystem by local operations and classical communication through ground-state entanglement. We prove two energy-entanglement inequalities for a minimal QET model. These relations help us to gain a profound understanding of entanglement itself as a physical resource by relating entanglement to energy as an evident physical resource.

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