  Recently, Motes, Gilchrist, Dowling & Rohde [Phys. Rev. Lett. 113, 120501
(2014)] presented a scheme for photonic boson-sampling using a fiber-loop
architecture. Here we show that the same architecture can be modified to
implement full, universal linear optics quantum computing, in various
incarnations. The scheme employs two embedded fiber-loops, a single push-button
photon source, three dynamically controlled beamsplitters, and a single
time-resolved photo-detector. The architecture has only a single point of
interference, and thus may be significantly easier to align than other schemes.
The experimental complexity of the scheme is constant, irrespective of the size
of the computation, limited only by fiber lengths and their respective loss
rates.

Quantum Physics