Bound Molecules in an Interacting Quantum Walk

Understand

We investigate a system of two atoms in an optical lattice, performing a quantum walk by state-dependent shift operations and a coin operation acting on the internal states.

• The atoms interact, e.g., by cold collisions, whenever they are in the same potential well of the lattice.
• Under such conditions they typically develop a bound state, so that the two atoms effectively perform a quantum walk together, rarely moving further from each other than a few lattice sites.
• The theoretical analysis is based on a theory of quantum walks with a point defect, applied to the difference variable.