Trapped ions are a promising approach to quantum computation. This approach uses a qubit state which is the atomic state and quantum motional state of a trapped ion to encode information, and uses laser-ion interactions to manipulate the qubit state. A major obstacle to the realization of a practical ion trap quantum computer is decoherence. In trapped ion quantum computation experiments, decoherence is dominated by the uncontrolled heating of ion motional states. In this thesis, we present the detailed microfabrication of several series of surface electrode linear Paul traps made from different electrode materials, followed by the ion motional heating experiment results for these traps. We demonstrate that the ion motional heating strongly depends on fabrication process. In particular, we explore how grain size and grain orientation affect the ion motional heating rate. This thesis is divided into two parts. In the first part, we describe the fabrication of gold, silver, aluminum and niobium traps from different processes, which results in various surface morphologies and grain structures. Ion motional heating rate measurements are then conducted both at cryogenic temperatures and at room temperature. We employ a physical model based on the fluctuating patch potential theory to explain the ion heating behavior. We use gold traps to study the temperature and frequency dependence of the ion heating. We use aluminum traps to study the ion heating dependence on the amorphous dielectric layer. And we use silver traps to study the ion heating dependence on the grain structure. These results suggest that excess ion heating could possibly be suppressed by suitable fabrication selection. In the second part, we present the process of using SU8 to fabricate a multilayer surface electrode point Paul trap, which has the advantage of allowing ion height variation within the same trap and enables testing of the distance dependence of ion heating.

Quantum mechanics, the subfield of physics that describes the behavior of very small (quantum) particles, provides the basis for a new paradigm of computing. First proposed in the 1980s as a way to improve computational modeling of quantum systems, the field of quantum computing has recently garnered significant attention due to progress in building small-scale devices. However, significant technical advances will be required before a large-scale, practical quantum computer can be achieved. Quantum Computing: Progress and Prospects provides an introduction to the field, including the unique characteristics and constraints of the technology, and assesses the feasibility and implications of creating a functional quantum computer capable of addressing real-world problems. This report considers hardware and software requirements, quantum algorithms, drivers of advances in quantum computing and quantum devices, benchmarks associated with relevant use cases, the time and resources required, and how to assess the probability of success.

This stimulating discussion of a rapidly developing field is divided into two parts. The first features tutorials in textbook style providing self-contained introductions to the various areas relevant to atom chip research. Part II contains research reviews that provide an integrated account of the current state in an active area of research where atom chips are employed, and explore possible routes of future progress. Depending on the subject, the length of the review and the relative weight of the 'review' and 'outlook' parts vary, since the authors include their own personal view and style in their accounts.

The development of scalable microfabricated ion traps with multiple segments for the realization of quantum computing is a challenging task in quantum information science. The research on the design, development, fabrication, and operation of the first European micro-trap is shown in this thesis. This chip-based micro-trap is an outstanding candidate towards experiments for a future quantum processor with trapped single ions. In the experiments coherent quantum state manipulation is demonstrated, and sideband cooling to the motional ground state is realized. The heating rate is determined and the applicability for quantum computation is proven. Furthermore planar trap designs are investigated - a planar microparticle trap was built and operated. A linear microfabricated planar trap was operated, showing the proof of concept of a novel designed and fabricated Y-shaped planar trap.

Conventional ion traps require machined electrode surfaces to form the electric trapping field. This class of electrode presents significant obstacles when attempting to miniaturize ion traps to create portable mass spectrometers. Machined electrodes lose required precision in shape, smoothness, and alignment as trapping dimensions decrease. Simplified electrode geometries are essential to open the way to miniaturized ion traps.

Following successful demonstrations of quantum algorithms and error correction with a handful of trapped ions in a macroscopic, machined Paul trap, there is a growing effort to move towards microfabricated traps with all the electrodes on a single chip. These traps, known as surface-electrode ion traps, are more amenable to being shrunk in size and replicated, or integrated with optical components and electronic devices. However, in the shift towards surface-electrode traps, and as traps are miniaturized in general, laser beams are brought closer to electrode surfaces, exacerbating laser-induced charging. Because of their charge, trapped ions are extremely sensitive to stray charges that accumulate on the trap surface. The DC potentials caused by stray charge displace the ion from the null of the RF trapping field, resulting in a fast, driven motion of the ion (known as micromotion) which hinders quantum operations by broadening transitions and causing decoherence. In a surface trap, micromotion detection is difficult as the laser beams used for measurement typically cannot crash into the trap, obscuring ion offsets out of the trap plane. Existing methods for micromotion detection permit ion positioning accurate to the ground state wavepacket size (of order 10 nm), but cannot identify ion offsets out of the trap plane with the same accuracy. Schemes for sensitive compensation often have restrictive requirements such as access to a narrow atomic transition. We introduce a new approach, which permits out-of-plane micromotion compensation to within 10s of nanometers with minimal overhead. Our technique synchronously detects ion excitation along the trap axes when it is driven by secular-frequency sidebands added to the RF electrodes; the excitation amplitude is proportional to the offset from the RF null. We make a detailed theoretical comparison with other techniques for micromotion compensation and demonstrate our technique experimentally.