The Geonium Chip: engineering a scalable planar Penning trap

In this thesis is presented the realisation of `The Geonium Chip', a novel planar Penning trap. The chip is designed with the goal of building a truly scalable planar Penning trap, while retaining the accuracy of 3D traps. Manufactured with conventional metalon- silicon microfabrication techniques, the chip takes the 5 electrodes of the compensated cylindrical trap and projects them onto a ground-plane surface, thus forming the basis for its layout by reducing the electrode shape to an array of at rectangular surfaces. In this thesis I describe the conception, design and construction of a full cryogenic set-up, including the magnetics, for trapping and observing a single electron in the Geonium Chip Penning trap. The cyclotron mode of the trapped electron lies in the microwave regime, and thus the Geonium Chip has the potential to become a powerful building block for quantum microwave circuits, with coherent coupling to the cyclotron degree of freedom. This will also allow non-destructive measurement and interaction with the spin state of the electron. The development of the experimental process is detailed from scratch including the design, fabrication, and testing of the Geonium Chip, as well as the design, fabrication and testing of the experimental apparatus. The original solutions and space saving designs developed as part of the construction process are detailed, such as the custom on-chip cryogenic vacuum chamber, planar magnetic field source, and the LED-based electron loading system. The vacuum chamber and control systems are also described, and the in-house manufacturing capabilities of the Geonium group are detailed at length, with an emphasis on rapid prototyping high-accuracy components suitable for experimental use. The apparatus built within this PhD is within a few weeks of performing the first loading of electrons into the chip trap.