Cavity-based non-destructive detection in ultracold gases

Gokul V. I, Arun Bahuleyan, Raghuveer Singh, S. P. Dinesh, V. R. Thakar and S. A. Rangwala

Cavity quantum electrodynamics studies the interaction of atoms with the electromagnetic mode of an optical cavity. Placing an atom within a cavity modifies its emission properties either by changing the spontaneous emission rates (weak coupling regime) or by coherent exchange of energy between atom and cavity mode (strong coupling regime). When there are multiple atoms (NC) inside the cavity mode volume, collective effects emerge. As a result, the atom-cavity system shows vacuum Rabi splitting (VRS), which directly depends on the √NC (collective strong coupling regime). This makes the cavity a frequency-sensitive detection tool for measuring state-dependent interactions. To demonstrate rapid, continuous cavity-based measurements, we experimentally measure time evolution in a multilevel atomic system and show the potential of cavity-based measurements for state detection, even when there are many participating energy levels. Later, extending cavity-based detection scheme for molecules is explored.