Andreas Wallraff, "Measuring the correlations of a Microwave Frequency Single Photon source"

Wed, Jun 16, 2010, 2:00 pm to 3:00 pm
PCTS Seminar Room

ABSTRACT: Circuit quantum electrodynamics (QED) allows for excellent control and measurement of the quantum mechanical properties of qubits, photons and their interactions. As a result, circuit QED is an ideal test bed to investigate the quantum nature of light. In our experiments we prepare a complete family of zero and one photon superposition states in a high quality on-chip resonator by controlling single qubit Rabi and qubit-cavity vacuum Rabi oscillations. By detecting the emitted radiation passed through a 50/50 beam-splitter integrated on the same chip we are able to perform time-resolved measurements of the cavity field quadratures, photon number, and first and second order correlation functions. We characterize the prepared field states and also show that we are able to cool a small thermal background field present in the cavity to below its thermal equilibrium value. Single photon coherence is observed in first-order and photon antibunching in second-order correlation measurements of the propagating fields. We suggest that any correlation which can be expressed in terms of the cavity field operators can be measured by using beam splitters, homodyne detection and efficient real time signal processing. CONTACT: Toni Sarchi. SPEAKER AFFILIATION: ETH, Zurich. SPONSOR: Jason Petta.