Coupling of magnetic and optomechanical structuring in cold atoms

Self-organized phases in cold atoms as a result of light-mediated interactions can be induced by coupling to internal or external degrees of the atoms. There has been growing interest in the interaction of internal spin degrees of freedom with the optomechanical dynamics of the external center-of-mass motion. We present a model for the coupling between magnetic and optomechanical structuring in a J = 1/2 -> J' = 3/2 system in a single-mirror feedback scheme, which is representative of a larger class of diffractively coupled systems such as longitudinally pumped cavities and counterpropagating-beam schemes. For negative detunings, a linear stability analysis demonstrates that optical pumping and optomechanical driving cooperate to create magnetic ordering. However, for long-period transmission gratings the magnetic driving will strongly dominate the optomechanical driving, unless one operates very close to the existence range of the magnetic instability. At small lattice periods, in particular at wavelength-scale periods, the optomechanical driving will dominate.

Automated summary

This study investigates self-organized phases in cold atoms due to light-mediated interactions with the coupling of internal spin degrees of freedom and optomechanical dynamics. The results show that the dominance of magnetic driving or optomechanical driving depends on the lattice periods, with the magnetic driving being stronger for long-period transmission gratings and the optomechanical driving being dominant at small lattice periods.