Theoretical Benchmark Reached
Here's some very exciting news out of the University of Oxford. Researchers have reached the next milestone in the quest toward building quantum computers. Scientists from the Engineering and Physical Sciences Research Council (EPSRC)-funded Networked Quantum Information Technologies Hub (NQIT) have achieved a quantum logic gate with an absolutely astonishing 99.9% precision. This is especially exciting since that rate is the theoretical benchmark required to actually build a quantum computer.
The difference between the processing power of current computing technology and the power quantum computers would hold is vast. Unsurprisingly, the knowledge needed to understand quantum computing and how its achieved is intense. As EurekAlert mentions, a (very) simplified analogy is often used to at least give a slight idea of the magnitude of the technology. In the analogy, today's conventional computing technology is compared to reading every book in a library, one by one. Quantum computing technology is compared to reading every book in a library, all at once. This is the kind of computing power we're talking about.
According to a co-author of the paper, Professor David Lucas, of Oxford University's Department of Physics and Balliol College, Oxford, the concept of 'quantum entanglement' is the center of the technology. Another analogy, if you'll allow it, to discuss this concept is that of identical twins across the world feeling each other's pain or emotions. Imagine this on an atomic scale. Prof. Lucas explains, "quantum entanglement...describes a situation where two quantum objects -- in our case, two individual atoms -- share a joint quantum state. That means, for example, that measuring a property of one of the atoms tells you something about the other."
The Oxford researchers were looking to place atoms in a quantum logic gate. This is when two separate atoms are put into a state of entanglement. Previously experts have shown that it is theoretically impossible to build a quantum computer where the precision of this logic gate falls below 99%. The theoretical threshold needs to be 99.9%. Hence the excitement over this paper, published in the journal Physical Review Letters.
The next step is to achieve a logic gate with 99.99% precision.
Of course, this is not the end of the knowledge we need to build before we can construct a quantum computer. As Prof. Lucas says, "A quantum logic gate on its own does not constitute a quantum computer, but you can't build the computer without them."