Double-path dark-state laser cooling in a three-level system

We present a detailed analysis of a robust and fast laser cooling scheme [J. Cerrillo, Phys. Rev. Lett. 104, 043003 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.043003] on a three-level system. A special laser configuration, applicable to trapped ions, atoms, or cantilevers, designs a double-path quantum interference that eliminates the blue sideband in addition to the carrier transition, thus excluding any heating process involving up to one-phonon interactions. As a consequence, cooling achieves vanishing phonon occupation up to first order in the Lamb-Dicke parameter expansion. Underlying this scheme is a combined action of two cooling schemes which makes the proposal very flexible under constraints of the physical parameters such as laser intensity, detuning, or optical access, making it a viable candidate for experimental implementation. Furthermore, it is considerably faster than existing ground state cooling schemes. Its suitability as a cooling scheme for several ions in a trap and three-dimensional cooling is shown. © 2018 American Physical Society.