Experimental realization of plaquette resonating valence bond states   with ultracold atoms in optical superlattices
  The concept of valence bond resonance plays a fundamental role in the theory of the chemical bond and is believed to lie at the heart of many-body quantum physical phenomena. Here we show direct experimental evidence of a time-resolved valence bond quantum resonance with ultracold bosonic atoms in an optical lattice. By means of a superlattice structure we create a three-dimensional array of independent four-site plaquettes, which we can fully control and manipulate in parallel. Moreover, we show how small-scale plaquette resonating valence bond states with s- and d-wave symmetry can be created and characterized. We anticipate our findings to open the path towards the creation and analysis of many-body RVB states in ultracold atomic gases. 
Sylvain Nascimb\`ene, Yu-Ao Chen, Macros Atala, Monika Aidelsburger,   Stefan Trotzky, Bel\'en Paredes, Immanuel Bloch
cond-mat.quant-gas quant-ph