Events

Tue March 26, 2019 4:00 pm

Antoine Browaeys: Many-body physics with arrays of individual Rydberg atoms

Location:Harvard Jefferson 250
Antoine Browaeys, Institut Optique
Ten Minute Talk:"Schrödinger-cat states in Rydberg atom arrays" by Ahmed Omran

This talk will present our effort to control and use the dipole-dipole interactions between cold Rydberg atoms in order to implement spin Hamiltonians useful for quantum simulation. We trap individual atoms in arrays of optical tweezers separated by few micrometers and excite them to Rydberg states. We create almost arbitrary geometries of the arrays with unit filling in two and three dimensions up to about 70 atoms. 

We have demonstrated the coherent energy exchange in chains of Rydberg atoms resulting from their resonant dipole-dipole interaction and its control by addressable lasers. This interaction realizes the XY spin model. We use this control to study elementary excitations in a di-merized spin chain featuring topological properties, thus implementing the Su-Schrieffer-Heeger model. We have observed the edge states in the topological condition. We explored the regime beyond the linear response by adding several excitations, which act as hard-core bosons. Using the van der Waals interaction between atoms, we have also implemented the quantum Ising model in one-dimensional chains with periodic boundary conditions and two-dimensional arrays containing up to about 50 atoms. We measure the dynamics of the excitation for various strengths of the interactions and compare the data to numerical simulations of this many-body system. 

This control of an ensemble of interacting Rydberg atoms demonstrates an interesting platform for quantum simulation using neutral atoms, complementary to the other platforms based on ions, magnetic atoms or dipolar molecules.

Fluorescence images of individual atoms trapped in arrays of optical tweezers separated by a few micrometers

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