Haytham Chibani

Antiresonance phase shift in strongly coupled cavity QED.

We investigate phase shifts in the strong coupling regime of single-atom cavity quantum electrodynamics. On the light transmitted through the system, we observe a phase shift associated with an antiresonance and show that both its frequency and width depend solely on the atom, despite the strong coupling to the cavity. This shift is optically controllable and reaches 140°--the largest ever reported for a single emitter. Our result offers a new technique for the characterization of complex integrated quantum circuits.

Three-Photon Correlations in a Strongly Driven Atom-Cavity System

The quantum dynamics of a strongly driven, strongly coupled single-atom-cavity system is studied by evaluating time-dependent second- and third-order correlations of the emitted photons. The coherent energy exchange, first, between the atom and the cavity mode, and second, between the atom-cavity system and the driving laser, is observed. Three-photon detections show an asymmetry in time, a consequence of the breakdown of detailed balance. The results are in good agreement with theory and are a first step towards the control of a quantum trajectory at larger driving strength.

Quantum optics with a new cavity QED setup

We report on a new cavity QED setup with asymmetric mirrors, optimized for high photon flux. Novel photon statistics and real-time feedback experiments are now possible.

Feedback cooling of a single neutral atom

Maxwell realized in a famous thought experiment, which is nowadays known as Maxwells demon, that the thermodynamic parameters of a system can be altered by performing feedback on the systems individual constituents. Here we report on the implementation of a related scheme to cool the motion of a single neutral atom.

Observation of time-dependent third-order correlations in cavity QED

A lot of information about a physical system can be gained by characterizing the light field that is emitted. Measurements of second-order intensity correlation functions have become a standard tool to observe the conditional dynamics of various fundamental systems in quantum optics. Here, we present - for the first time - measurements of the time-dependent, third-order intensity correlation function of a genuine quantum system. It consists of a neutral 85Rb atom strongly coupled to a single mode of a high-finesse optical cavity. In order to excite higher-order dressed states of the Jaynes-Cummings ladder we use relatively strong probe powers corresponding to steady state empty-cavity photon numbers as high as 20.