6533b833fe1ef96bd129b726

RESEARCH PRODUCT

Time-resolved observation of coherent multi-body interactions in quantum phase revivals

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Interactions between microscopic particles are usually described as two-body interactions, although it has been shown that higher order multi-body interactions could give rise to novel quantum phases with intriguing properties. This paper demonstrates effective six-body interactions in a system of ultracold bosonic atoms in a three-dimensional optical lattice. The coherent multi-particle interactions observed here open a new window for simulations of effective field theories and may help to enable the realization of novel topologically ordered many-body quantum phases. Interactions between microscopic particles are usually described as two-body interactions, although it has been shown that higher-order multi-body interactions could give rise to new quantum phases with intriguing properties. Here, effective six-body interactions are demonstrated in a system of ultracold bosonic atoms in a three-dimensional optical lattice. Interactions lie at the heart of correlated many-body quantum phases1,2,3. Typically, the interactions between microscopic particles are described as two-body interactions. However, it has been shown that higher-order multi-body interactions could give rise to novel quantum phases with intriguing properties. So far, multi-body interactions have been observed as inelastic loss resonances in three- and four-body recombinations of atom–atom and atom–molecule collisions4,5,6. Here we demonstrate the presence of effective multi-body interactions7 in a system of ultracold bosonic atoms in a three-dimensional optical lattice, emerging through virtual transitions of particles from the lowest energy band to higher energy bands. We observe such interactions up to the six-body case in time-resolved traces of quantum phase revivals8,9,10,11, using an atom interferometric technique that allows us to precisely measure the absolute energies of atom number states at a lattice site. In addition, we show that the spectral content of these time traces can reveal the atom number statistics at a lattice site, similar to foundational experiments in cavity quantum electrodynamics that yield the statistics of a cavity photon field12. Our precision measurement of multi-body interaction energies provides crucial input for the comparison of optical-lattice quantum simulators with many-body quantum theory.