Reliable transport through a microfabricated<i>X</i>-junction surface-electrode ion trap

Abstract

We report the design, fabrication, and characterization of a microfabricated\nsurface-electrode ion trap that supports controlled transport through the\ntwo-dimensional intersection of linear trapping zones arranged in a\nninety-degree cross. The trap is fabricated with\nvery-large-scalable-integration (VLSI) techniques which are compatible with\nscaling to a larger quantum information processor. The shape of the\nradio-frequency (RF) electrodes is optimized with a genetic algorithm to\nminimize axial pseudopotential barriers and to minimize ion heating during\ntransport. Seventy-eight independent DC control electrodes enable fine control\nof the trapping potentials. We demonstrate reliable ion transport between\njunction legs, trapping of ion chains with nearly-equal spacing in one of the\ntrap's linear sections, and merging and splitting ions from these chains.\nDoppler-cooled ions survive more than 10^5 round-trip transits between junction\nlegs without loss and more than sixty-five consecutive round trips without\nlaser cooling.\n