Quantum walks in optical lattices

The use of neutral atoms trapped in optical lattices to implement quantum walks on the line and on the circle was proposed. The quantum walk was performed in position space by periodically shifting the lattices and manipulating the internal states of the atom(s) by homogeneous laser pulses. Read-out of the resulting probability distribution was performed via fluorescence measurements. As such, the influence of decoherence and imperfections in manipulation of internal state of the atoms were investigated and showed a transition taking place from the ideal quantum walk to the classical random walk for increasing errors.