"Quantum computers can efficiently render every physically possible quantum environment, even when vast numbers of universes are interacting. Quantum computation is a qualitatively new way of harnessing nature," according to David Deutch, an Israeli-British physicist at the University of Oxford who pioneered the field of quantum computation and is a proponent of the many-worlds interpretation of quantum mechanics. Quantum computers, says Deutch, have the potential to solve problems that would take a classical computer longer than the age of the universe.
Not only do quantum computers promise a dramatic increase in speed over classical computers in a variety of computational tasks; they are designed to complete tasks that even a supercomputer would not be able to handle. In recent years, there has been a rapid development in quantum technology the realization of a full-sized quantum computer is still very challenging.
While it is still an exciting open question which architecture and quantum objects will finally lead to the outperformance of conventional supercomputers, current experiments show that some quantum objects are better suited than others for particular computational tasks.
The huge advantage of photons -- a particular type of bosons -- lies in their high mobility. The research team from the University of Vienna in collaboration with scientist from the University of Jena (Germany) has recently realized a so-called boson sampling computer that utilizes precisely this feature of photons. They 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. Amazingly, one can record the outcome of the computation rather trivially: one measures how many photons exit in which output of the network," explains Philip Walther from the Faculty of Physics.
The Daily Galaxy via University of Vienna