Quantum simulators based on ultra-cold rydberg atoms
In this project we aim to exploit the strong interactions between atoms excited to high-lying Rydberg
states for the purposes of quantum simulation. In recent years, quantum simulators have attracted
much interest as an interesting alternative to all-purpose quantum computers. The idea behind a
quantum simulator is to create a model system in the laboratory for a Hamiltonian (which could
represent, e.g., a high-Tc superconductor or some other system of fundamental interest) whose ground
state or dynamics cannot be calculated on a classical computer because of the exponentially large
size of the Hilbert space involved.
In our research we create small clouds of ultra-cold atoms in magneto-optical traps or in dipole
traps and then drive excitations to Rydberg states using a two-color laser scheme. We then field
ionize and detect the Rydberg atoms and extract information from the system through the full counting
statistics of the detection events. In this way, we have been able to measure the phase diagram of an
off-resonantly excited Rydberg gas in the dissipative regime, in which the excitation takes place on
a timescale that is longer than the lifetime of the Rydberg states. In the future we want to extend
this approach to excitation dynamics in the coherent regime and to perform finite-size scaling-type
experiments in order to derive the critical exponents of the system. This will allow us to perform a
benchmarking of our strongly correlated system, which is a crucial step towards a useful quantum
simulator based on Rydberg atoms.
Experimental setup for creating and detecting Rydberg excitations in an ultra-cold gas
Phase diagram of an off-resonantly excited Rydberg gas in the dissipative regime as a function of the detuning and the driving Rabi frequency [N. Malossi et al., Phys. Rev. Lett. 113, 023006 (2014)]