Narrowband composite two-qubit phase gates

Abstract

We propose a method to construct composite two-qubit gates with narrowband profiles with respect to the spin-spin coupling. The composite sequences are selective to the variations in the amplitude and duration of the spin-spin coupling, and can be used for highly-selective qubit addressing with greatly reduced cross talk, quantum logic spectroscopy, and quantum sensing.

Strategies for practical advantage of fault-tolerant circuit design in noisy trapped-ion quantum computers

“…Therefore choosing a different set of physical gates could also make available crosstalk resistant circuits for the realization of other logical building blocks. Furthermore, crosstalk errors could be suppressed by utilizing inherently crosstalk insensitive gate operations like composite pulses [86,87], or active suppression schemes, where additional laser fields are applied to the qubit register that destructively interfere with unwanted leakage light at neighboring ion positions. Exploiting the fact that for each ion a global phase can be freely chosen might allow for crosstalk resistant qubit mappings even in the case of random but constant crosstalk phases.…”