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Centre for Quantum Technologies
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the newspaper TODAY
Every day, we share information about ourselves over telephone calls, email messages and Internet transactions. Our lives are increasingly digitised and our social connections literally networked. Thanks to United States government documents leaked last year, we know how little of this data traffic is private. Even encrypted data is vulnerable. In documents disclosed by Edward Snowden, the US National Security Agency was revealed to have a progra...
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Keeping secrets in a world of spies and mistrust - CQT's Director Artur Ekert explains how it's possible
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In the future, quantum cryptography might secure transactions such as identification at ATMs. (This is an artist's impression.) An international research team including some of our scientists has demonstrated a proof-of-principle protocol known as 1-2 random oblivious transfer
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Meet our newest Principal Investigator: Troy Lee is a gymnast, juggler and theoretical computer scientist
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Here's Physics Nobel Prize winner Dave Wineland telling a story of quantum clocks and quantum computers. The interview was filmed here in Singapore last year, after we were lucky enough to have him give a talk.
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In our interview this week, meet Sai, a CQT Research Fellow whose interests include quantum metrology and South Indian cooking
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Atom lasers for space! New Scientist magazine is reporting on a paper by CQT postdocs Paul Condylis and Daniel Sahagun Sanchez with their former lab-mates in Greece
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Meet Peng Kian, a PhD student whose quantum optics project is motivated by measuring the size of exoplanets
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You bet your arse he can! Go that guy!
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We've announced the winners of our Quantum Shorts flash fiction competition!

Top prize goes to "The Knight of Infinity" by Brian Crawford, a tale of a wealthy, grieving widower planning a grand experiment. It is an energetic and ultimately touching tale that buzzes with ideas about the multiverse and the disparate realities this interpretation of quantum theory creates.

We have prizes for five more stories, too. Follow the link to read them all...
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Great!  Fun story!
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Want to really stretch your mind? Here's a post by CQT Visiting Research Prof John Baez on the possibility of a connection between quantum entanglement and wormholes in spacetime
Wormholes and Quantum Entanglement

An apparent contradiction in what most physicists believe about black holes - the firewall problem - is making some very good physicists reach for some very crazy-sounding ideas to find a way out.  In particular, Maldacena and Susskind have come up with the idea that any pair of quantum-entangled particles is actually connected by a wormhole

Entanglement is a spooky way for far-away particles to be correlated.  It's been seen in the lab, but it's only possible thanks to quantum mechanics.  The first ones to make a fuss over it were Einstein, Podolsky and Rosen, back in 1935.

A wormhole is a spooky way for two far-away regions of space to be connected by a shortcut: a kind of 'tunnel in space', as shown here.  Nobody has ever seen one, but they're theoretically possible thanks to general relativity.  The first ones to make a fuss over it were Einstein and Rosen, back in 1935.

So, superficially, it makes sense that there should be a connection between wormholes and entanglement.  But when you learn enough physics, you'll see that Maldacena and Susskind's proposal sounds completely hare-brained.

But when you learn more physics - maybe more than enough? - you might decide there's some merit to this idea after all.  At the Centre for Quantum Technologies last summer, +Jamie Vicary and I noticed some interesting connections between wormholes and quantum entanglement.  We now have a paper out!

In it, we study quantum gravity in a universe where space is just 2-dimensional, not 3-dimensional like ours.  It's not realistic, but it has one huge advantage: there's a working theory of what quantum gravity could be like when space is 2-dimensional, so you can calculate stuff!  

So, we calculate what happens when a wormhole forms, and we show the ends look like a particle and its antiparticle (this was already known), and we note that this particle-antiparticle pair is entangled.  In fact it's completely entangled: any piece of information you might want to know about one can also be found in the other.  

However, in a sense that Jamie and I make precise, this entanglement is 'fake'.  The reason is that the two ends of the wormhole are not independent things.  They're just two views of the same thing... and, technically, it doesn't count as entanglement when something is 'entangled with itself'.  This fact is crucial to how Maldacena and Susskind want to get around the firewall problem. 

For more, try this blog article I wrote:

This has links to other stuff, including our paper, but also some blog articles explaining the firewall problem, the paper by Maldacena and Susskind, and the original Einstein-Podolsky-Rosen and Einstein-Rosen papers (in English).

#spnetwork #quantumGravity arXiv:1401.3416
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A research centre at the National University of Singapore, also known around the web as quantumlah.
Welcome to the google+ page for the Centre for Quantum Technologies in Singapore. Add us to your circles to stay up to date with our news and events.

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CQT is a Research Centre of Excellence hosted by the National University of Singapore. It brings together quantum physicists and computer scientists to explore the quantum nature of reality and quantum possibilities in information processing.