Arrays of cold atoms

Many-body Physics in Atom Arrays

Fluorescence image of atoms in a randomly loaded one-dimensional optical tweezer array. After imaging, we perform real-time feedback to sort atoms into a defect free array, and take a second fluorescence image for verification.

In our lab, we study coherent many-body physics in highly controlled arrays of individual neutral rubidium-87 atoms. Each atom is independently trapped in vacuum in an optical tweezer, enabling realtime control of each atomic position in space. We can deterministically initialize registers of up to 51 atoms in arbitrary geometries in 1D.

Once the atoms are prepared in their programmed positions and pumped into their ground electronic states, we introduce interactions among them by using lasers to excite them to Rydberg states. The large interactions between nearby Rydberg atoms dominate the dynamics of the system, and by varying the distance between atoms and therefore the effective interaction strengths, we can probe qualitatively different physical regimes.

The Rydberg Hamiltonian for one-dimensional atom arrays exhibits a ground state phase diagram with several ordered phases.

Using this platform, we can probe both ground-state physics of the phase diagram, as well as out-of-equilibrium dynamics. For example, we have observed for the first time the unexpected dynamics that occur after preparing a ‘Rydberg crystal’ and then quenching the system out of equilibrium.

We aim to further develop this platform for quantum simulation in 2D, and to use the platform for quantum optimization algorithms with more than one hundred qubits.


M. Endres et. al. Science 354, 6315: 1024-1027 (2016).

H. Bernien et. al. Nature 551: 579-584 (2017).