"A large number of physical phenomena, such as high-temperature superconductivity, involve the complex interaction of many quantum particles. Simulating the dynamics of these many-body systems is a difficult challenge for computational physics, as the size of the Hilbert space of the system increases exponentially with the number of particles, rapidly saturating the available memory of classical computers.

Thus, for several years, an intense effort has been made on a global scale, from atomic physics to condensed matter, to make interact assemblies of two-level systems, or qubits, in a controlled manner with the aim of surpassing computers.

Among the various platforms being considered for quantum simulation, Rydberg atom arrays are one of the most advanced systems. Atoms in the ground state, trapped in optical tweezers, are arranged in a well-defined arbitrary geometry before being transferred into low-momentum Rydberg states using laser pulses. Due to the strong dipole-dipole coupling between the Rydberg levels, atoms interact with their neighbors. Currently, most simulators use these low angular momentum states and their relatively short lifetime limits the simulation time available.

Our team is looking to implement a simulator based on circular Rydberg atoms. With their toric wave function, circular states have a lifetime nearly four orders of magnitude longer than their low-angular momentum counterparts, paving the way for system simulation over a much longer duration. Finally, this simulator will be built from strontium atoms, an alkaline earth with two valence electrons offering remarkable properties such as the ability to trap circular atoms in simple optical tweezers or to detect Rydberg states using the core electron in a non-destructive way."

Reasearch unit : Laboratoire Kastler-Brossel / Cavity Quantum Electrodynamics group

Advisor : Sébastien Gleyzes

Keywords : Quantum physics, Atomic physics, Quantum simulation, Quantum information, Rydberg atoms