Hmm, yeah, so I guess we now have quantum computing… A quantum computer at University of Illinois at Urbana-Champaign solved a problem without even running a program. The researchers were able to determine an answer to an algorithm by combining quantum computation and quantum interrogation (a technique that makes use of wave-particle duality to search a region of space without actually entering that region) in an optical-based quantum computer through a process called “counterfactual computation”.
While I might not understand what they did here, I know it is amazing. If you don’t know too much about quantum physics, take a look at this Wikipedia article on Schrodinger’s Cat, it helps lay down the foundations for some of this stuff.
According to the University’s press release the experiment was set up in the following manner:
Utilizing two coupled optical interferometers, nested within a third, Kwiat’s team succeeded in counterfactually searching a four-element database using Grover’s quantum search algorithm. “By placing our photon in a quantum superposition of running and not running the search algorithm, we obtained information about the answer even when the photon did not run the search algorithm,” said graduate student Onur Hosten, lead author of the Nature paper. “We also showed theoretically how to obtain the answer without ever running the algorithm, by using a ‘chained Zeno’ effect.”
Through clever use of beam splitters and both constructive and destructive interference, the researchers can put each photon in a superposition of taking two paths. Although a photon can occupy multiple places simultaneously, it can only make an actual appearance at one location. Its presence defines its path, and that can, in a very strange way, negate the need for the search algorithm to run.
“In a sense, it is the possibility that the algorithm could run which prevents the algorithm from running,” Kwiat said. “That is at the heart of quantum interrogation schemes, and to my mind, quantum mechanics doesn’t get any more mysterious than this.”
Now, all we need to do is to wait for quantum computing to become available in personal computers. 
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