  Fundamental aspects of ultracold collisions between identical bosonic or
fermionic dipoles are studied under quasi-two-dimensional (Q2D) confinement. In
the strongly dipolar regime, bosonic and fermion species are found to share
important collisional properties as a result of the confining geometry, which
suppresses the inelastic rates irrespective of the quantum statistics obeyed. A
potential negative is that the confinement causes dipole-dipole resonances to
be extremely narrow, which could make it difficult to explore Q2D dipolar gases
with tunable interactions. Such properties are shown to be universal, and a
simple WKB model reproduces most of our numerical results. In order to shed
light on the many-body behavior of dipolar gases in Q2D we have analyzed the
scattering amplitude and developed an energy-analytic form of the
pseudopotentials for dipoles. For specific values of the dipolar interaction,
the pseudopotential coefficient can be tuned to arbitrarily large values,
indicating the possibility of realizing Q2D dipolar gases with tunable
interactions.
