Strongly Correlated Quantum Walks in Optical Lattices

March 13, 2015
Figure 3

Fig 3: Formation of repulsively bound pairs. [Reprinted with permission from AAAS*]

Full control over the dynamics of interacting, indistinguishable quantum particles is an important prerequisite for the experimental study of strongly correlated quantum matter and the implementation of high-fidelity quantum information processing. Grad student Philipp Preiss, postdoc Eric Tai, and members of Prof. Markus Grener's group demonstrate such control over the quantum walk - the quantum mechanical analog of the classical random walk - in the regime where dynamics are dominated by interparticle interactions. Using interacting bosonic atoms in an optical lattice, the physicists directly observed fundamental effects such as the emergence of correlations in two-particle quantum walks, as well as strongly correlated Bloch oscillations in tilted optical lattices. Their approach, reposrted in the latest issue of Science*, can be scaled to larger systems, greatly extending the class of problems accessible via quantum walks.

*P.M. Preiss, R.Ma, M.E. Tai, A. Lukin, M. Rispoli, P. Zupancic, Y. Lahini, R. Islam, and M. Greiner, "Strongly correlated quantum walks in optical lattices," Science 347: 622713 (Mar 2015) DOI: 10.1126/science.1260364