Mikrostrukturierte segmentierte Paul-Falle mit einstellbarem Magnetfeldgradienten

Strings of laser cooled ions stored in microstructured Paul traps (microtraps) have promising potential for quantum information science. They provide a system which can be screened from a decohering environment, accurately prepared, manipulated and state selectively detected with efficiency close to unity. Magnetic field gradients allow for addressing trapped ions in frequency space. Furthermore, coupling of the ions' motional and spin states and long range spin-spin coupling of the ions' internal states are induced by such a gradient. This method is called Magnetic Gradient Induced Coupling, MAGIC.
In this thesis, the design, construction and first characteriszation of a novel microtrap with an integrated solenoid is reported. The solenoid is designed to create a high magnetic field gradient per dissipated heat. The microtrap consists of three layers stacked onto each other. The outer layers provide a trapping potential, while the inner layer creates the switchable magnetic field gradient. Another specialty of this trap is the 33 pairs of DC electrodes, allowing to move the ions along the trap axis and to adjust the range and the strength of the ions' spin-spin interactions. The microtrap is fixed on top of a ceramic block that provides the necessary electrical connections via thick film printed wires, a technique adopted in the context of microtraps for the first time, and in addition acts as a vacuum interface. The volume of the vacuum chamber is quite small, allowing for pressures in the low 10 -11 mbar range. In this microtrap, 172 Yb + -ions are trapped, cooled and shuttled over a distance of about 2mm. Trapped ions are used as magnetic field gradient probes, with a relative magnetic field precision of Delta B/B 0 = 7 · 10 -6 . The addressing of two ions with the MAGIC method in the solenoid's magnetic field gradient is demonstrated.