Spatially uniform single-qubit gate operations with near-field microwaves and composite pulse compensation

Abstract

We present a microfabricated surface-electrode ion trap with a pair of\nintegrated waveguides that generate a standing microwave field resonant with\nthe 171Yb+ hyperfine qubit. The waveguides are engineered to position the wave\nantinode near the center of the trap, resulting in maximum field amplitude and\nuniformity along the trap axis. By calibrating the relative amplitudes and\nphases of the waveguide currents, we can control the polarization of the\nmicrowave field to reduce off-resonant coupling to undesired Zeeman sublevels.\nWe demonstrate single-qubit pi-rotations as fast as 1 us with less than 6 %\nvariation in Rabi frequency over an 800 um microwave interaction region. Fully\ncompensating pulse sequences further improve the uniformity of X-gates across\nthis interaction region.\n