Abstract

I will present a new and original method to directly measure the density of a Rydberg gas very accurately. All conventional density measurements of a dilute gas are based on the determination of both the gas volume and the particle number (e.g. with the help of an applied radiation). Instead, we probe the nearest neighbour distibution in the gas, which depends parametrically on its density. This can be done by using long-range dipole-dipole interactions in a Rydberg gas. By sweeping an applied electric field, we experimentaly induce adiabatic transitions between pair states, mediated by the dipole-dipole interaction between the two atoms of the pair. The adiabatic transition efficiency is our control knob to probe the nearest neighbour distribution and is tuned via the field sweeping rate.

In addition, such adiabatic transitions should leave the pair of Rydberg atoms in an entangled state. I will propose a method to reveal the atom entanglement based on quantum fluctuations in a two-atom Rabi oscillation measurements.