Searches for New Particles Including Dark Matter with Atomic, Molecular and Optical Systems

New particles can manifest their effects in many settings, ranging from effects on sub-atomic to galactic length scales. The nature of these effects depends on the specific particles and their non-gravitational interactions. In this chapter, we give a brief overview of how atomic, molecular and optical systems can be used to search for new particles. To illustrate the basic principles behind these methods, we focus on the simplest class of particles, namely new spinless bosons.