In many cases before a new technology emerged to conquer a market, it existed in a variety of forms with different advantages and disadvantages inherit to their separate designs and constructions. Quantum computers are currently going through this phase as new and fundamentally different architectures are made and tested. Researchers at the University of Vienna have recently built and tested a 'boson sampling' computer, which uses photons, a type of boson, and a complex optical network to perform calculations.
Photons, the quanta of light, are being considered for use in many quantum computer designs, thanks to the relative ease they can be made with and their very high mobility. The design the researchers created takes advantage of this mobility by putting them through a network with multiple paths available to the photons. While a classical particle will be limited to a single path, a quantum mechanical particle can enter a superposition and take multiple at the same time. By then counting the number of photons to exit each output of the network, the computer is able to complete a calculation.
This ability of quantum computers to utilize superposition gives them the power to perform computations that are nearly impossible with a classical computer. Ironically though, to confirm this boson sampling computer was operating correctly, the researchers needed a classical computer to verify the quantum computer's output.
Source: University of Vienna