A novel surface-electrode trap design enabling electrically-driven non-Gaussian operations for trapped-ion CVQC

We investigate the use of trapped ions for continuous-variable quantum computing (CVQC).  CVQC, a quantum computing (QC) paradigm relatively unexplored in trapped ions, employs systems with large Hilbert spaces, e.g. the motional modes of ions in a trap. These modes can be controlled using external RF electric fields, with gate speeds comparable to those achieved in traditional qubit-based trapped-ion QC. In addition, the technical complexity of applying an RF voltage to an electrode is less than using laser beams or strong magnetic field gradients. Gate operations driven by RF electric fields that are useful for trapped-ion CVQC have already been demonstrated experimentally by other groups. These gates are all Gaussian however, and universal CVQC requires at least one non-Gaussian gate.  The non-Gaussian gates used so far rely on laser beams, so the operations needed for universal CVQC cannot be carried out with RF electric fields alone. The best method to implement a non-Gaussian gate with RF electric fields remains an open question. As a possible solution, we have designed a new type of surface-electrode ion trap. We propose that this trap can, by generating an RF cubic potential, carry out a set of non-Gaussian gates, including trisqueezing, at speeds practical for QC.