Scientists Create New Type of Quantum Computer: The Boson Sampling Computer

Quantum computers hold enormous potential for speeding up information processing speeds and revolutionizing the way computers solved problems. Now, scientists have succeeded in prototyping a new and highly resource efficient model of quantum computer--the boson sampling computer. It's a huge leap forward for quantum computers.

Quantum computers work by manipulating quantum objects as, for example, individual photons, electrons or atoms, and by harnessing the unique quantum features. This particular feature promises a dramatic increase in speed over classical computers--especially when it comes to a specific combinational optimization problem. In fact, quantum computers have the potential to complete tasks that even a supercomputer would not be able to handle.

While these quantum computers could revolutionize computing, though, it's been very hard to actually create a full-sized quantum computer. That said, enormous strides have been made in the area, including this latest prototype.

The so-called boson sampling computer utilizes photons, a particular type of bosons. These particles have high mobility, which makes them extremely valuable in a quantum computer. In order to create the boson sampling computer, the researchers inserted photons into a complex optical network where they could propagate along many different paths.

"According to the laws of quantum physics, the photons seem to take all possible paths at the same time. This is known as superposition," said Philip Walther from the Faculty of Physics in a news release. "Amazingly, one can record the outcome of the computation rather trivially: one measures how many photons exit in which output of the network."

Classical computers rely on exact descriptions of optical networks in order to calculate the propagation of the photons through these circuits. Calculating the propagation of the photons for a few dozen photons and an optical network with merely a hundred inputs and outputs is impossible even for today's fastest classical supercomputer. Yet for the boson sampling computer, this feat is within reach. The newest computer is actually built based on a theoretical proposal by scientists at the Massachusetts Institute of Technology.

"It is crucial to verify the operation of a boson sampling computer by comparing its outcome with the predictions of quantum physics. Ironically, this test can only be performed on a classical computer," said Max Tillmann, first author of the study detailing the new computer, in a news release. "Fortunately, for small enough systems classical computers are still able to accomplish this."

The new computer could pave the way to creating more quantum computers. Eventually, it could replace classical computers when it comes to solving challenging problems.

The study detailing the boson sampling computer is published in the journal Nature Phototonics.