Berlin 2014 – scientific programme

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A: Fachverband Atomphysik

A 52: Characterization and control of complex quantum systems SYQS 1 (with Q, MO, MS, MP, AGjDPG)

A 52.3: Talk

Friday, March 21, 2014, 12:00–12:15, Audimax

Antiresonance in a Strongly-Coupled Atom-Cavity System — •Christoph Hamsen, Christian Sames, Haytham Chibani, Paul A. Altin, Tatjana Wilk, and Gerhard Rempe — Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching

The strongly-coupled atom-cavity system has proven useful for the observation of fundamental quantum effects. Recently, it has found application as a building block for more complex structures in elementary quantum circuits for quantum information processing. Moreover, large networks of strongly-coupled systems have been proposed for simulation of quantum phase transitions. However, due to the strong coupling these compound systems cannot be treated perturbatively, but require a holistic analysis of all constituents making characterization a challenging task.

Here, we provide a route to address this challenge. It is based on an experiment where, by heterodyne detection of the light transmitted through a cavity containing a single atom, we see a hitherto unobserved negative phase shift which is associated with an antiresonance. The linewidth and frequency of this antiresonance are solely determined by the atom. The corresponding phase shift can be optically controlled via the AC stark shift and reaches values of up to 140° - the largest ever reported for a single emitter. We explain how this opens up new routes towards characterization of complex quantum circuits.