Prospects for single-photon sideband cooling of optically trapped neutral atoms

Year: 2021

Authors: Berto F.; Perego E.; Duca L.; Sias C.

Autors Affiliation: Politecnico di Torino, Torino, 10129, taly; Istituto Nazionale di Ricerca Metrologica (INRiM), Torino, 10135, Italy; European Laboratory for Nonlinear Spectroscopy (LENS), Sesto Fiorentino, 50019, Italy; Istituto Nazionale di Ottica Del Consiglio Nazionale Delle Ricerche (CNR-INO), Sesto Fiorentino, 50019, Italy

Abstract: We propose a cooling scheme for realizing single-photon sideband cooling on particles trapped in a state-dependent optical potential. We develop a master rate equation from an ab initio model and find that in experimentally feasible conditions it is possible to reduce the average occupation number of the vibrational levels in one dimension by more than 90% by applying a frequency sweep on the cooling laser that sequentially cools all the motional states. Notably, this cooling scheme works also when a particle experiences a deeper trap in its internal ground state than in its excited state, a condition for which conventional single-photon sideband cooling does not work. In our analysis, we consider two cases: a two-level particle confined in an optical tweezer, and Li atoms confined in an optical lattice, and we find conditions for efficient cooling in both cases. The results from the model are confirmed by a full quantum Monte Carlo simulation of the system Hamiltonian. Our findings provide an alternative cooling scheme that can be applied in principle to any particle, e.g., atoms, molecules, or ions, confined in a state-dependent optical potential.


Volume: 3 (4)      Pages from: 043106-1  to: 043106-8

More Information: We thank M. Zaccanti, G. Roati, and F. Scazza for helpful discussions, and M. Inguscio for continuous support. We thank G. Bertaina for support in the use of computational resources at INRiM. The authors wish to acknowledge that the simulation has been performed with the open-source scientific python framework [34]. This work was financially supported by the European Research Council Starting Grant PlusOne (Grant Agreement No. 639242), and the MIUR FARE grant UltraCrystals (Grant No. R165JHRWR3).
KeyWords: Optical pumping; Optical lattices and traps
DOI: 10.1103/PhysRevResearch.3.043106