Morten P. Bakker,1 Ajit V. Barve,2 Thomas Ruytenberg,1 Wolfgang Löffler,1 Larry A. Coldren,2 Dirk Bouwmeester,1,3 and Martin P. van Exter1 1Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, Netherlands 2Departments of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, USA 3Department of Physics, University of Cali...

The interplay of quantum fluctuations with nonlinear dynamics is a central topic in the study of open quantum systems, connected to fundamental issues such as decoherence and the quantum-classical transition and practical applications such as coherent information processing and the development of mesoscopic sensors and amplifiers . With this context in mind, we here present a computational stud...

We investigate a cavity quantum electrodynamic effect, where the alignment of two-dimensional freely rotating optical dipoles is driven by their collective coupling to the cavity field. By exploiting the formal equivalence of a set of rotating dipoles with a polymer we calculate the partition function of the coupled light-matter system and demonstrate that it exhibits a second order phase trans...

An important development in modern physics is the emerging capability for investigations of dynamical processes for open quantum systems in a regime of strong coupling for which individual quanta play a decisive role. Of particular signiÐcance in this context is research in cavity quantum electrodynamics which explores quantum dynamical processes for individual atoms strongly coupled to the ele...

We have employed radio-frequency trapping to localize a single Ca-ion in a high-finesse optical cavity. By means of laser Doppler cooling, the position spread of the ion’s wavefunction along the cavity axis was reduced to 42 nm, a fraction of the resonance wavelength of ionized calcium (λ = 397 nm). By controlling the position of the ion in the optical field, continuous and completely determini...

A quantum computer processes quantum information which is stored in “quantum bits” (qubits). [1] If a small set of fundamental operations, or “universal quantum logic gates,” can be performed on the qubits, then a quantum computer can be programmed to solve an arbitrary problem [2]. The explosion of interest in quantum computation can be traced to Shor’s demonstration in 1994 that a quantum com...

Doppler and transit broadening effects inherent in a thermal atomic beam reduce the size of quantum fluctuations in a cavity QED system. A cold continuous atomic beam would reduce these effects, but would not eliminate the different atom–field couplings associated with the random distribution of atoms throughout the cavity. We present results that describe the effect that this has on quantum fl...

These lectures are based on work done in collaboration with many students, postdocs and colleagues, including particularly my friends and colleagues Bibliography 93 iii iv S.M. Girvin Circuit QED 1 Key papers students may wish to consult: • Blais et al., 'Cavity quantum electrodynamics for superconducting electrical circuits: An architecture for quantum computation,' Phys. Rev.

Photon correlation measurements reveal the response of the conditional evolution of the cavity QED system to a novel quantum feedback protocol. A photodetection collapses the state of the system and triggers a feedback pulse with an adjustable delay and amplitude that alters the intensity driving the system. The conditional evolution of the system freezes into a new steady state where it reside...

We calculate the integrated-pulse quantum efficiency of single-photon sources in the cavity quantum electrodynamics (QED) strong-coupling regime. An analytical expression for the quantum efficiency is obtained in the Weisskopf-Wigner approximation. Optimal conditions for a high quantum efficiency and a temporally localized photon emission rate are examined. We show the condition under which the...