Experimental quantum device aims to reveal every possible future at once

9 Apr 2019

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Australian and Singaporean researchers have created a quantum device that aims to see all possible futures and develop super-powered AI.

If it were possible for anyone to see the myriad of different possibilities an action would lead to, you might think it would lead to chronic indecision. Now, a collaboration between Griffith University in Australia and Nanyang Technological University (NTU) Singapore has managed to achieve something quite similar using a quantum computer.

Publishing its findings to Nature Communications, the international research team said that it has created an experimental quantum device that can generate all possible futures in a simultaneous quantum superposition.

“When we think about the future, we are confronted by a vast array of possibilities,” said assistant professor Mile Gu of NTU Singapore who led the development of the quantum algorithm that underpins the prototype.

“These possibilities grow exponentially as we go deeper into the future. For instance, even if we have only two possibilities to choose from each minute, in less than half an hour there are 14m possible futures. In less than a day, the number exceeds the number of atoms in the universe.”

What the team realised during development was that a quantum computer could examine all of these futures by placing them in a quantum superposition, a concept similar to Schrödinger’s famous cat, which is simultaneously alive and dead.

This was achieved with a specially created photonic quantum information processor where potential future outcomes of a decision are represented by the locations of photons. The team then demonstrated that the state of the quantum device was a superposition of multiple potential futures, weighted by their probability of occurrence.

‘Still in the dark about what quantum computers can do’

The machine has already demonstrated one application: measuring how much our bias towards a specific choice in the present impacts the future.

Lead author of the study, Farzad Ghafari of Griffith University, explained: “By interfering these superpositions with each other, we can completely avoid looking at each possible future individually. In fact, many current artificial intelligence (AI) algorithms learn by seeing how small changes in their behaviour can lead to different future outcomes, so our techniques may enable quantum-enhanced AIs to learn the effect of their actions much more efficiently.”

Right now, the device can only simulate 16 futures at most, but the research team said there’s nothing to stop it being scalable infinitely.

Prof Geoff Pryde of the team said “this is what makes the field so exciting”.

“It is very much reminiscent of classical computers in the 1960s,” he added. “Just as few could imagine the many uses of classical computers in the 1960s, we are still very much in the dark about what quantum computers can do.”

Colm Gorey was a senior journalist with Silicon Republic