It was recently reported that scientists were able to overcome some of the problems with data degradation caused by computing in a quantum environment, and now Nature reports that physicists were able to build the first-ever working quantum network. Though, the the fibre optic network is in its infancy, as researchers reported a mere .2 percent accuracy in data that had been transferred. Still, the experiment has proven that quantum networks are possible.
A quantum computer makes direct use of quantum mechanical phenomena to perform operations on data, and could be able to solve specific problems much faster than any traditional, transistor-based computer - The problem with quantum computing has been errors in computation. A classical computer understands data as bits, which can either have a values of 1 or 0. Qubits on the other hand, can have a value of 1, 0 or both simultaneously, which is known as superposition, and allows quantum computers to conduct millions of calculations at once. But there are errors, known as quantum decoherence, caused by things like heat, electromagnetic radiation and defective materials.
German physicists from the Max Planck Institute of Quantum Optics built the network, which bounces single, data-carrying rubidium atoms through optical fiber, while emitting one proton. The proton in turn maintains the polarization state of the rubidium atom, or, it's supposed to, hence the resulting .2 % data transmission accuracy - quantum computing relies on the coordinated motion of atomic particles. It's been difficult keeping protons aligned in a singular environment. Once researchers have this step sorted out, it is at least proven that a quantum network can exist.