Qubits, qutrits, and ququads stored in single photons from an atom-cavity system

Annemarie Holleczek; Oliver Barter; Gunnar Langfahl-Klabes; Axel Kuhn

Proc. SPIE 9377, Advances in Photonics of Quantum Computing, Memory, and Communication VIII

One of today's challenge to realize computing based on quantum mechanics is to reliably and scalably encode information in quantum systems. Here, we present a photon source to on-demand deliver photonic quantum bits of information based on a strongly coupled atom-cavity system. It operates intermittently for periods of up to 100 mu s, with a single-photon repetition rate of 1MHz, and an intra-cavity production efficiency of up to 85%. Due to the photons inherent coherence time of 500ns and our ability to arbitrarily shape their amplitude and phase profile we time-bin encode information within one photon. To do so, the spatio-temporal envelope of a single photon is sub-divided in d time bins which allows for the delivery of arbitrary qu-d-its. The latter is done with a fidelity of > 95% for qubits, and 94% for qutrits verified using a newly developed time-resolved quantum-homodyne technique.

Related tags
NQIT Author