  We demonstrate single-atom trapping in two-dimensional arrays of microtraps
with arbitrary geometries. We generate the arrays using a Spatial Light
Modulator (SLM), with which we imprint an appropriate phase pattern on an
optical dipole trap beam prior to focusing. We trap single $^{87}{\rm Rb}$
atoms in the sites of arrays containing up to $\sim100$ microtraps separated by
distances as small as $3\;\mu$m, with complex structures such as triangular,
honeycomb or kagome lattices. Using a closed-loop optimization of the
uniformity of the trap depths ensures that all trapping sites are equivalent.
This versatile system opens appealing applications in quantum information
processing and quantum simulation, e.g. for simulating frustrated quantum
magnetism using Rydberg atoms.

Atomic Physics;Quantum Gases;Quantum Physics