Development of a segmented ion trap for quantum control of multi-species ion chains

Daniel Kienzler, Hsiang-Yu Lo, Ben Keitch, Joseba Alonso, Florian Leupold, Ludwig de Clercq, Frieder Lindenfelser, Roland Habluetzel, Martin Sepiol, and Jonathan Home

Institute for Quantum Electronics, ETH, Zurich, Switzerland

We are developing a new experimental setup for quantum information processing, simulation and state engineering with trapped atomic ions. The system is designed to simultaneously trap both beryllium and calcium ions using a segmented linear Paul trap. We have designed and optimized a trap with three zones for quantum control and two zones for separation of ion strings; each step of trap fabrication has now been run independently. Preparation, cooling and quantum control of both ion species will require a wide range of laser light sources, many of which are not commercially available. For beryllium we have developed a 6 W source of 626 nm light using sum-frequency generation of two commercial high-power fibre lasers - further frequency doubling of the light will use BBO crystals in resonant cavities. The laser sources required for the calcium ion are commercial systems, which we have stabilized to home-built optical cavities. In order to detect fluorescence emitted from both ion species simultaneously, we have designed a high numerical-aperture imaging system consisting of in-vacuum objective lenses plus dual-channel optics outside the vacuum. This work presents a number of key experimental steps towards precision control of trapped ions.