A hybrid system of a membrane oscillator coupled to ultracold atoms

Sanghita Sengupta, Dennis P. Clougherty

Philipp Treutlein

Andreas Jöckel, Aline Faber, Tobias Kampschulte +3 more

Philipp Christoph, Tobias Wagner, Hai Zhong +4 more

A promising route to novel quantum technologies are hybrid quantum systems, which combine the advantages of several individual quantum systems. We have realized a hybrid atomic-mechanical experiment consisting of a Si 3 N 4 membrane oscillator cryogenically precooled to 500 mK and optically coupled to a cloud of laser cooled 87 Rb atoms. Here, we demonstrate active feedback cooling of the oscillator to a minimum mode occupation of corresponding to a mode temperature of T min ≈ 200 μ K. Furthermore, we characterize in detail the coupling of the membrane to the atoms by means of sympathetic cooling. By simultaneously applying both cooling methods we demonstrate the possibility of preparing the oscillator near the motional ground state while it is coupled to the atoms. Realistic modifications of our setup will enable the creation of a ground state hybrid quantum system, which opens the door for coherent quantum state transfer, teleportation and entanglement as well as quantum enhanced sensing applications.

Stephan Camerer, Maria Korppi, Andreas Jöckel +3 more

We have realized a hybrid optomechanical system by coupling ultracold atoms to a micromechanical membrane. The atoms are trapped in an optical lattice, which is formed by retroreflection of a laser beam from the membrane surface. In this setup, the lattice laser light mediates an optomechanical coupling between membrane vibrations and atomic center-of-mass motion. We observe both the effect of the membrane vibrations onto the atoms as well as the backaction of the atomic motion onto the membrane. By coupling the membrane to laser-cooled atoms, we engineer the dissipation rate of the membrane. Our observations agree quantitatively with a simple model.

Carlo Sias, Lothar Ratschbacher, Christoph Zipkes +1 more