Characterization of Inner Control Electrode Shapes for Multi-Layer Surface-Electrode Ion Traps

Trapped ions are a leading platform for quantum information processing. The quantum CCD architecture enables all-to-all connectivity between atomic ion qubits in dedicated registers and can be implemented in microfabricated surface-electrode traps. The development of novel fabrication techniques over the past years has enabled the design of surface-electrode ion traps with increasingly complex multi-layer structures. Yet the control electrodes remain mostly unchanged and of rectangular shape. We propose and characterize novel asymmetric inner control electrode shapes for simultaneous axial and radial control in multi-layer surface traps and verify their capabilities in realistic use-case scenarios for ion transport and shim compensation. Eliminating the need for commonly used additional outer control electrodes, asymmetric inner control electrodes increase the compactness and space efficiency of surface-electrode traps. They concurrently reduce the number of control signals and their voltage magnitudes, making them compatible with integrated Cryo-CMOS circuits.