Login required to started new threads

Login required to post replies

Quantum Teleportation across the Danube Demonstrated
Quote | Reply
squib from scientific american...

The Danube River is known for its beauty and has been immortalized in song. Now researchers have employed the water body as a testing ground for quantum teleportation. Scientists report today in the journal Nature that they have successfully teleported photons more than 600 meters across the famous waterway.

Rupert Ursin and his colleagues at the Institute for Experimental Physics in Vienna fired a laser through a barium borate crystal to generate two pairs of photons. One pair is entangled, which means that if something disturbs the state of one, the other feels the effects as well--even when they are not physically connected. By separating the entangled pair, the scientists successfully transported information about the state of one photon to the other. Using fiber-optic cable laid under the water in sewer pipes, together with microwaves sent across the air above the water, three distinct states were teleported across the Danube. Over the course of a 28-hour experimental run, the system was correct 97 percent of the time. The results indicate that quantum teleportation is feasible over long distances and under real-world conditions, the scientists say. “Our result,” they write, “is a step towards the implementation of a quantum repeater, which will enable pure entanglement to be shared between distant parties in a public environment and eventually on worldwide scale.” --Sarah Graham
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [johnthesavage] [ In reply to ]
Quote | Reply
Well....... I just fixed my rear derailure.
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [johnthesavage] [ In reply to ]
Quote | Reply
Very cool. I remember reading an article in SciAm about a year or two ago when they were first starting this type of experiments. They were also testing similar techniques for secure communications... really makes your head spin.
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [JimmyChuck] [ In reply to ]
Quote | Reply
yep. the problem of having quantum computers to increase security of cryptographic algorithms is that then with the same quantum computer, you can do a brute force search in polynomial time (i.e. really fast) which defeats the purpose...
so far, I know of only one theoretical crypto quantum algo that would be secure

(but its' fun)
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [johnthesavage] [ In reply to ]
Quote | Reply
does this mean I'm going to wake up as Scott Bakula?


--------------------------------------------------------------------
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
Francois - what the hell did you just say? About 15% of that post made any sense to me , and that was only because you have two and three letter words in there...

------------------------------------------------------------------------

http://pavlov.psyc.queensu.ca/~psyc382/rockgold.html
(Norman Rockwell's "Do Unto Others")
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [goobie] [ In reply to ]
Quote | Reply
quantum computers represent data not as bits (0 and 1s) but as combinations of 'a little bit of 0' with 'a little bit of 1'.
These are theoretical so far.
With these quantum computers, you can do many things much faster.

For instance going from one town, visiting many towns, coming back to the same without going twice through the same town, and spending a minimum amount of cash on gas is a difficult problem. Right now the solution that works is to try all the combinations of town (Very inefficient).

With quantum computers, you can do that much faster (in 'polynomial' time) using quantum algorithms.

so in cryptography, you can use quantum algorithm to encrypt very securely, very efficiently...but if an attacker also has a quantum computer, he can try all possible combination with his quantum computer, without spending too much time, because the quantum computer will do things much faster (will be able to try plenty of combinations of crypto keys at once)...

Better?
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
riiiiiiiiiiight. I *think* I get it, but only in the loosest possible terms. But thanks for trying to make it clearer!

Here's where computers and my field overlap. On page two of the paper (if you can bothered looking at it) is a kinetic map that makes my head spin. That someone managed to turn that into any kind of algorithm/simulation makes me realise that I am about to become a dinosaur...

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14751248

------------------------------------------------------------------------

http://pavlov.psyc.queensu.ca/~psyc382/rockgold.html
(Norman Rockwell's "Do Unto Others")
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [goobie] [ In reply to ]
Quote | Reply
LOL :-)

check

Ultimate zero and one: computing at the quantum frontier

really good introduction to quantum computing. not for computer scientists at all, but to give an idea of computers could become...some fun stuff...

not my research area though...
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
Is this like the teleporters in Star Trek?

_______________________________________________
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
not quite (yet)...right now we can only teleport energy or information (photons)...
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
Is the cat dead or alive?
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
I hear ya... don't understand it fully, but I think I have an idea of what you said.

But I was able to find the original article I was thinking about (from 1997 so maybe it's a bit outdated)... http://www.sciam.com/...8EF21&sc=I100322

Something along the lines of the state of the particle you're looking at gets changed just because you looked at it (the Heisenberg principle at work). The article doesn't specifically speak to how secure communications would be accomplished, but it hints towards that end.

Honestly I'm not sure my propeller spins fast enough to understand any of it.

-Santiago
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
right now we can only teleport energy or information Yeah, but aren't matter and energy the same thing?

(photons)... Torpedoes away!








"People think it must be fun to be a super genius, but they don't realize how hard it is to put up with all the idiots in the world."
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [elund] [ In reply to ]
Quote | Reply
Schroedinger didn't tell me
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [Francois] [ In reply to ]
Quote | Reply
Are there any practial applications for this technology that the average guy might see? Obviously, everyone is always up to buy the fastest computer technology, but this sounds like it would be far past being useful to the layperson.

Slowguy

(insert pithy phrase here...)
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [slowguy] [ In reply to ]
Quote | Reply
Imagine how much quicker you could tell that a thread wasn't worth contributing to...

------------------------------------------------------------------------

http://pavlov.psyc.queensu.ca/~psyc382/rockgold.html
(Norman Rockwell's "Do Unto Others")
Quote Reply
Re: Quantum Teleportation across the Danube Demonstrated [slowguy] [ In reply to ]
Quote | Reply
in a near future, I don't think so...in 10 years, it may be possible...
actually there are other new computing paradigm, like DNA computing (can see that as something super massively parallel), quantum computing etc...
Quote Reply