Recently quantum computing company D-Wave Systems announced that it had broken the 1000 qubit barrier – an important breakthrough, according to experts who speculate on the fascinating physics behind quantum computing.
Quantum computers encode information in quantum bits, or qubits, which can be in a quantum superposition of zero and one states, and therefore they can process information in ways that have no equivalent in classical computing by exploiting subtle quantum phenomena such as quantum entanglement.
In a short video released in January before the recent D-Wave announcement, venture capitalist Steve Jurvetson, a Managing Director of Draper Fisher Jurvetson who sits on the D-Wave Board of Directors, explains in simple terms how quantum computers can be so efficient because they harness the computing power of a huge number of parallel universes.
First introduced in 1957 by theoretical physicist Hugh Everett, the Many-Worlds Interpretation (MWI) of quantum physics says that the quantum superpositions extend across parallel universes. A qubit in a quantum superposition of zero and one states exists in two parallel universes. Similarly, two qubits require four parallel universes, and so forth. And a system of 1000 qubits would span a huge number of parallel universes.
Jurvetson notes that Google bought the first D-Wave quantum computers, and Google researchers consider quantum computing as a path to Artificial Intelligence (AI), with its first practical applications being image recognition, machine learning and deep learning.
The only physical explanation of how quantum computing works is that it uses the computational resources of parallel universes, says Jurvetson in the video. This interpretation is often mentioned by science writers, but it’s mostly ignored by those professional scientists who are afraid of losing reputation by showing too much imagination. Venture capitalists see nothing wrong with imagination, if they can use it to make more money. Of course, imagination is good, but quantum physics is counter-intuitive and “visual” explanations should be taken with caution.
Since the number of parallel universes whose computing power is harnessed by a quantum computer increases exponentially with the number of qubits, a quantum computer with a few thousands of qubits could have a computing power greater than all existing computers combined, and adding even more qubits could result in a machine with more computational power than the entire universe.
If quantum computers keep doubling the number of qubits every few years, Moore’s Law – the observed doubling in performance of computer systems every two years – would become even faster. “It’s a Moore’s Law on top of Moore’s Law,” says Jurvetson commenting the image above, titled “Rose’s Law” after D-Wave’s founder and CTO Geordie Rose.
Unfortunately, the practical difficulty of building quantum computers increases exponentially with the number of qubits, so there is the possibility that quantum computing research might hit a roadblock. Jurvetson speaks of “a 10 percent chance that it doesn’t hit some roadblock.”