Controlling and Detecting Spin Correlations of Ultracold atoms in Optical Lattices

Stefan Trotzky (1) , Yu-Ao Chen (1) , Ute Schnorrberger (1) , Patrick Cheinet (2) , Immanuel Bloch (1)

1 QUANTUM - QUANTUM group, Institute for Physics
2 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique

We report on the controlled creation of a valence bond state of delocalized effective-spin singlet and triplet dimers by means of a bichromatic optical superlattice. We demonstrate a coherent coupling between the singlet and triplet states and show how the superlattice can be employed to measure the singlet-fraction employing a spin-blockade effect. Our method provides a reliable way to detect and control nearest-neighbor spin correlations in many-body systems of ultracold atoms. Being able to measure these correlations is an important ingredient in studying quantum magnetism in optical lattices. We furthermore employ a SWAP operation between atoms which are part of different triplets, thus effectively increasing their bond-length. Such a SWAP operation provides an important step towards the massively parallel creation of a multiparticle entangled state in the lattice.

Domaines: Optique [physics.optics]

Stefan Trotzky, Yu-Ao Chen, Ute Schnorrberger, Patrick Cheinet, Immanuel Bloch. Controlling and Detecting Spin Correlations of Ultracold atoms in Optical Lattices. Physical Review Letters, 2010, 10 (26), pp.265303. ⟨10.1103/PhysRevLett.105.265303⟩. ⟨hal-00746816⟩