BREAKING THE CHAIN: Entanglement sudden death, or ESD, is the sudden and complete loss of correlation, or entanglement, between two or more quantum systems.
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It sounds like a tiebreaker round in a mixed martial arts bout: entanglement sudden death, or ESD. In actuality it is a mysterious phenomenon by which entangled quantum objects—two electrons, for example, whose properties are linked by some instantaneous connection across space—can suddenly break off their relationship.
In classical physical systems, decay is usually asymptotic—that is, the correlation between two objects approaches, but never reaches, zero. But ESD does not follow this pattern—when it strikes, the degree of entanglement drops to zero in a finite time, severing the quantum link clean.
In a review paper in this week's Science, physicists Ting Yu of the Stevens Institute of Technology in Hoboken, N.J., and Joseph Eberly of the University of Rochester address the phenom and what it means for the future of quantum computing. (They wrote a similar paper in the same journal in 2007 as a commentary on a concurrent study that was among the first to experimentally verify the existence of ESD.) Essentially, Yu and Eberly wrote in this week's paper, ESD remains a mystery, and one that might cause problems in developing quantum systems that rely on entanglement, such as the transmission and storage of information.
In particular, ESD can arise when two sources of environmental "noise" act to disrupt an entangled state. Each source would individually induce a more gradual asymptotic decay, but in tandem they can trigger ESD. This might have practical implications in quantum computing, as ours is a world of constant fluctuation—even a vacuum is alive with vibrations of energy. "In reality," Yu says, "multiple noises are almost universal."
Quantum memory—the long-term storage of information in quantum bits, or qubits—will be most vulnerable to ESD, Yu says, since more transitory processes could theoretically be sped up enough to be completed before ESD kicked in.
Christopher Monroe, a physicist who heads a leading quantum information group at the University of Maryland, College Park, believes that the speed of practical quantum systems will obviate most ESD concerns. "I see this concept as an interesting new angle in describing entanglement," he says, "although it probably does not impact or add roadblocks to the quest to build large entangled states for applications in quantum information science and fundamental quantum physics."
If viable quantum computers or information-processing systems are to be built, Monroe notes, "we need nearly perfect entangled states," adding that the strength of such entanglements would likely preclude ESD. "The [upper] thresholds for sudden-death entanglement are way below the more stringent thresholds we are currently aiming for," he says.
At the same time, "the concept of quantum entanglement remains murky," Monroe says, and concepts such as ESD "hopefully can help us get a better glimpse at what entanglement is and means."
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6 Comments
Add CommentI already knew that thru metaphysics. Hehehehehe....
Reply | Report Abuse | Link to thisIf you think about it, If you could entangle atoms in a stable entaglement, why then couln't you creat FTL comunications. If it's posible to create an instantanious reaction, and a Satabel engangled state, regurdless of distance, Then Asronauts on Mars could have a realtime conversation with their families on Earth. At least I don't see why they couldn't.
Reply | Report Abuse | Link to thisIf you think about it, If you could entangle atoms in a stable entaglement, why then couln't you creat FTL comunications. If it's posible to create an instantanious reaction, and a Satabel engangled state, regurdless of distance, Then Asronauts on Mars could have a realtime conversation with their families on Earth. At least I don't see why they couldn't.
Reply | Report Abuse | Link to thisAnubit - read up on entanglement. You can't create entanglement at a distance. The entangled particles must originate from a single particle. Further, even if you are holding onto one of the particles and your receipient at the other end of the universe has the other, you can't send a message. If you observe the particle and it says spin up, you know your recipient will see spin down. But you can't CAUSE your particle to be Spin up and thus can't send any information. FTL communications will likely require the bending or breaking of space-time, through, for example, a wormhole.
Reply | Report Abuse | Link to thisThe phenomenon of ESD desrves further elucidation as it suggests a mechanism which depends upon a maximum velocity of entanglement. This would itself be an interesting study as it supports the currently held belief that entanglemebnt is a refelection of the phase wave and group wave velocity, with a product of c^2. The net consequnce would be a maximum phase wave velocity of c^2.
Reply | Report Abuse | Link to thisMoreover using this concept and energy equivalence and quantum physics can be derived from first principles. See: The formulation od harmonic quintessence and a fundamental energy equivalence equation. Physics Essays 23:311-319.
i somehow have just begun loving the concept of quantum entanglement and it feels weird to witness another concept called ESD...????...!!!!...
Reply | Report Abuse | Link to thisits like what Feynman said "if you are saying that you understand quantum it means that you are either bluffing or you might be crazy"
CRAZY seems a lot better though