  We consider the feasibility of observing a trap-induced resonance [Stock et
al., Phys. Rev. Lett. 91, 183201 (2003)] for the case of two 133Cs atoms,
trapped in separated wells of a polarization-gradient optical lattice, and
interacting through a multichannel scattering process. Due to the anomalously
large scattering length of cesium dimers, a strong coupling can occur between
vibrational states of the trap and a weakly bound molecular state that is made
resonant by the ac-Stark shift of the lattice. We calculate the energy spectrum
of the two-atom system as a function of the distance between two potential
wells by connecting the solutions of the Schroedinger equation for the
short-range molecular potential to that of the long-range trap in a
self-consistent manner. The short-range potential is treated through a
multichannel pseudopotential, parametrized by the K matrix, calculated
numerically for atoms in free space in a close-coupling approximation. This
captures both the bound molecular spectrum as well as the energy-dependent
scattering for all partial waves. We establish realistic operating conditions
under which the trap-induced resonance could be observed and show that this
strong and coherent interaction could be used as a basis for high-fidelity
two-qubit quantum logic operations.
