Photons Walking the Line: A Quantum Walk with Adjustable Coin Operations
Abstract
We present the first robust implementation of a coined quantum walk over five steps using only passive optical elements. By employing a fiber network loop we keep the amount of required resources constant as the walker’s position Hilbert space is increased. We observed a nonGaussian distribution of the walker’s final position, thus characterizing a faster spread of the photon wave packet in comparison to the classical random walk. The walk is realized for many different coin settings and initial states, opening the way for the implementation of a quantumwalkbased search algorithm.
 Publication:

Physical Review Letters
 Pub Date:
 February 2010
 DOI:
 10.1103/PhysRevLett.104.050502
 arXiv:
 arXiv:0910.2197
 Bibcode:
 2010PhRvL.104e0502S
 Keywords:

 03.67.Ac;
 03.65.w;
 05.40.Fb;
 42.50.Dv;
 Quantum algorithms protocols and simulations;
 Quantum mechanics;
 Random walks and Levy flights;
 Nonclassical states of the electromagnetic field including entangled photon states;
 quantum state engineering and measurements;
 Quantum Physics
 EPrint:
 4 pages, 4 figures