arXiv:1705.10098 · Physical Review Letters

Light-Mediated Collective Atomic Motion in an Optical Lattice Coupled to a Membrane

Aline Vochezer, Tobias Kampschulte, Klemens Hammerer, Philipp Treutlein

Published Feb 14, 2018• 30 citations

Abstract

We observe effects of collective atomic motion in a one-dimensional optical lattice coupled to an optomechanical system. In this hybrid atom-optomechanical system, the lattice light generates a coupling between the lattice atoms as well as between atoms and a micromechanical membrane oscillator. For large atom numbers we observe an instability in the coupled system, resulting in large-amplitude atom-membrane oscillations. We show that this behavior can be explained by light-mediated collective atomic motion in the lattice, which arises for large atom numbers, small atom-light detunings, and asymmetric pumping of the lattice, in agreement with previous theoretical work. The model connects the optomechanical instability to a phase delay in the global atomic backaction onto the lattice light, which we observe in a direct measurement.

DOI: 10.1103/physrevlett.120.073602

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