Chan, Chor Hoi = 離子阱系統的研究 / 陳楚海. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 98-103). / Abstracts in English and Chinese. / Chan, Chor Hoi = Li zi jing xi tong de yan jiu / Chen Chuhai. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Review of ion traps --- p.1 / Chapter 1.1.2 --- Review of entanglement in ion trap systems --- p.2 / Chapter 1.1.3 --- Review of RWA and MRWA --- p.3 / Chapter 1.2 --- Continuous frequency modes in different configurations --- p.5 / Chapter 1.2.1 --- Configuration 1: simple one sided cavity --- p.6 / Chapter 1.2.2 --- Configuration 2: displaced cavity --- p.8 / Chapter 1.3 --- Coupling strength in the continuous frequency mode model --- p.10 / Chapter 2 --- Motional Rotating Wave Approximation (MRWA) --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Trapped ion in a classical light field --- p.13 / Chapter 2.3 --- MRVVA and a rough estimation of the effect of non-resonant terms --- p.14 / Chapter 2.4 --- Numerical comparison between the MRWA solution and the exact solution --- p.17 / Chapter 2.5 --- Numerical results --- p.18 / Chapter 2.6 --- Calculation in the weak coupling and small η limit --- p.28 / Chapter 3 --- Generation of entanglement between photon and phonon --- p.32 / Chapter 3.1 --- Single-ion model --- p.32 / Chapter 3.2 --- Generation of entanglement between photon and phonon through Raman process --- p.35 / Chapter 3.2.1 --- Resolvent method --- p.35 / Chapter 3.2.2 --- Solutions in the limit \/T / ΩT ≤ / 2ΩT《1 --- p.38 / Chapter 3.2.3 --- The long time wave function --- p.40 / Chapter 3.2.4 --- Generation of entanglement in the first red or blue side-band resonance --- p.41 / Chapter 3.2.5 --- Discussion --- p.43 / Chapter 3.3 --- Generation of entanglement by photon scattering --- p.45 / Chapter 3.3.1 --- Resolvent and the scattering matrix --- p.45 / Chapter 3.3.2 --- The long time wave function --- p.48 / Chapter 3.3.3 --- Discussion --- p.50 / Chapter 4 --- Entanglement between vibrational states of separate ions --- p.55 / Chapter 4.1 --- The cascaded system model --- p.55 / Chapter 4.1.1 --- Introduction and basic ideas --- p.55 / Chapter 4.1.2 --- Resolvent and state evolution --- p.57 / Chapter 4.1.3 --- Time-dependent nature of the entanglement --- p.65 / Chapter 4.2 --- Feedback system --- p.69 / Chapter 5 --- Quantum State Transfer --- p.75 / Chapter 5.1 --- Scattering of a photon --- p.75 / Chapter 5.2 --- Cascaded system --- p.76 / Chapter 5.3 --- Feedback system --- p.78 / Chapter 5.4 --- N injected photons --- p.79 / Chapter 5.5 --- General case --- p.80 / Chapter 5.5.1 --- One injected photon --- p.82 / Chapter 5.5.2 --- N injected photons --- p.83 / Chapter 6 --- Generalization to two ion-chains --- p.85 / Chapter 7 --- Sources of errors --- p.88 / Chapter 7.1 --- Attenuation in optical fiber --- p.88 / Chapter 7.2 --- Inclusion of other states --- p.88 / Chapter 7.3 --- Effect of approximation (3.4) --- p.90 / Chapter 7.4 --- Spontaneous emission --- p.92 / Chapter 8 --- Conclusion --- p.97 / Bibliography --- p.98 / Chapter A --- sin[θ+ η](b + bt)] in Fock state basis --- p.104 / Chapter B --- Adiabatic elimination --- p.105 / Chapter C --- Derivation of the phase operator S in the feedback process --- p.112 / Chapter D --- Quantum trajectory method --- p.114

<p> Trapped ions can be isolated from external perturbations such as collisions with other atoms or electric and magnetic field inhomogeneities. For this reason, trapped ions can be useful in spectral measurements, quantum information technology and studying quantum behaviour. In this thesis, I discuss a trapped-Mg+ apparatus for studying the quantum mechanics of atoms. I describe the laser interactions that allow us to coherently excite our atoms. I go on to discuss the actual apparatus for trapping ions and making precise measurements, the hyperfine structure of 25 Mg+ and a proposed linewidth measurement. </p> / Thesis / Master of Science (MSc)

Thesis (Ph. D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [164]-169).

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 235-246). Also available for download via the World Wide Web; free to University of Oregon users.

We investigate the coupling of a single trapped ion to a miniature optical cavity operating in the ultraviolet. Our cavity provides a source of single photons at a high rate into a single spatial mode. Using our apparatus, we have demonstrated the highest atom-cavity coupling rate achieved with a single ion by an order of magnitude. When the ion is continuously excited, we observe phase-sensitive correlations between emission into free-space and into the cavity mode, which can be explained by a cavity induced back-action effect on a driven dipole. We demonstrate coherent manipulation of a hyperfine qubit and ultra-short optical π rotations, which are essential tools for creation and detection of spin-photon entanglement. To this end, we have developed optical fibre-based Fabry-Perot cavities in the ultraviolet spectral range. These cavities operate near the primary dipole transition of Yb at 370 nm, and allow us to couple a pure atomic two-level system offered by a single trapped ion to the cavity mode. A new Paul trap apparatus in an ultra-high vacuum chamber has been built which allows for the integration of these cavities at very small ion-mirror separations. In order for independent operation of the trap, a compact system of diode lasers has been built which are stabilised to low-drift optical reference cavities. Coherent control of the hyperfine qubit in Yb 171 is achieved through application of microwave radiation, and ultra-short optical π rotations are performed with resonant light pulses derived from a frequency-doubled mode-locked titanium-sapphire laser. The experiment is controlled through a system of hardware and software which has been developed in a modular fashion and will allow for efficient control on the nanosecond time-scale when several such systems are interconnected. The success of our system opens the door to future experiments with trapped ions which will reach the strong coupling regime with a single ion. Furthermore, when operated in the fast-cavity regime, systems based on our approach will enable high-efficiency collection of photons from the ion into the single mode of an optical fibre. These systems will allow for the generation of distributed entanglement and will prove ideal as nodes in a larger quantum network of trapped ions.

The movement of tropical cyclones (TC) is studied numerically based on a two-dimensional barotropic model, using a previously developed non-oscillatory balanced scheme. The model of TC used here takes an exponential form, and its size and strength are selected to be of a middle scale. Without a background flow, TCs move in the northwest direction due to the beta effect. The amplitudes of high wavenumber modes of the asymmetric flow, that are believed to be responsible for the TC drift, are computed using Fourier analysis. The amplitude of wavenumber one and two modes are dominant, so they are indicators of beta conversion of energy. Also, the effect of the monsoon trough on the TC movement is investigated. The results show a sudden change of the TC propagation path, consistent with earlier work. These two studies correspond to previous works. Here, the effect of equatorially trapped waves such as Kelvin, Rossby, and Mixed Rossby Gravity, on the TC path is newly studied by varying the wavenumber and wave speed of the underlying waves. The effect of the waves is considered because they are believed to contribute to cyclogenesis. For studying the effect, the barotropic flow induced by these waves via momentum transport and its variation were simulated for 50 days, and some patterns are found in the change of maximum wind speed. At a given time during the simulation, a TC is injected and the effect of the background wave is analyzed. Using the wavefield of 11 cases from 10 days to 30 days, the trajectories are calculated, and their patterns appear to be stochastic. So, the patterns are identified by calculating the mean path and its spread. The trajectories of TCs are different for different time of the waves. Kelvin waves make small variations on the length and direction of the trajectory of TCs. On the contrary, Rossby waves cause a dramatic change in the TC path and yield longer trajectories. Meanwhile, TCs in MRG waves keep fairly the same direction and usually have longer traveling distance. These changes vary by wave conditions. Therefore, the three kinds of waves have different effects on the trajectories of the TC. For some peculiar cases, the movements are explained based on wavefields. / Graduate

Thesis (Ph. D.)--Open University. BLDSC no. DX225509.

Thesis (Ph. D.)--University of Colorado, 2001. / Includes bibliographical references.

published_or_final_version / abstract / toc / Physics / Master / Master of Philosophy

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