One of the difficulties that we’ll face on the road to quantum computers is creating something like the transistor: a device that facilitates the flow of bits of information in a computer.
The problem is that in a quantum computer bits of information are transferred via single photons that are harder to work with than the electrons we use today.
But according to HPCwire scientists from the Niels Bohr Institute at University of Copenhagen and from Harvard University have make progress:
The atom is brought close to the nanowire. Two photons are sent towards the atom and when they hit it an interaction occurs between them, where one imparts information to the other. The information is sent in bits which are either a one or zero digit, and the order of digits produces the message. (Today we can send information via an optic cable and each bit is made up of millions of photons.) In quantum optics each bit is just one photon. The photon has now received its message and the signal continues on its way. It is a step on the way to building a photon-transistor for a quantum computer.