2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/86869We show how to construct asymmetric optical barriers for atoms. These barriers can be used to compress phase space of a sample by creating a confined region in space where atoms can accumulate with heating at the single photon recoil level. We illustrate our method with a simple two-level model and then show how it can be applied to more realistic multi-level atoms.Atomic Physicstext