Quantum State Spectroscopy of Atom-Cavity Systems

Luis A. Orozco, G. T. Foster, J. Gripp +1 more

S. Haroche, F. Bernardot, M. Brune +2 more

The eigen frequencies of a system made of one (or a few Rydberg atom(s) in a high Q, nearly resonant microwave cavity are shifted with respect to both the unperturbed atomic and field mode ones.

S. L. Mielke, G. T. Foster, J. Gripp +1 more

We study the time response of a quantum optical system to a step excitation. The system is composed of a collection of N two-level atoms coupled to a single mode of the electromagnetic field of an optical cavity. The size of the step excitation is not limited to the low-intensity regime. Before the system reaches steady state there is an oscillatory exchange of energy between the atoms and the cavity. We compare the experimental results quantitatively with theoretical calculations and with previous transmission spectroscopy measurements.

Sun-Hyun Youn, Young-Tak Chough, Kyoungwon An

Dylan J. Young, Eric Yilun Song, Anjun Chu +6 more

We use an ensemble of laser-cooled strontium atoms in a high-finesse cavity to cleanly emulate the technique of rf spectroscopy employed in studies of BEC-BCS physics in fermionic superfluids of degenerate cold gases. Here, we leverage the multilevel internal structure of the atoms to study the physics of Cooper pair breaking in this system. In doing so, we observe and distinguish the properties of two distinct many-body gaps, the BCS pairing gap and the spectral gap, using nondestructive readout techniques. The latter is found to depend on the populations of the internal atomic states, reflecting the chemical potential dependence predicted in fermionic superfluids. This work opens the path for more fully exploiting the rich internal structure of atoms in cavity QED emulators to study both analogous systems and also more exotic states yet to be realized.

Fan QiuBo, Liu Dongdong, Han Baiping