High-fidelity, near-field microwave gates in a cryogenic surface trap
DPhil Thesis
Abstract:
We present a novel dynamical decoupling strategy for near field microwave
gradient driven, Mølmer-Sørensen style, two-ion quantum logic
gates, which suppresses errors from both fluctuations in the qubit frequency
and imperfection in the decoupling drive itself. Using a microwaveintegrated
surface-trap which is operated cryogenically at ∼ 25K and a
magnetically insensitive 43Ca+ qubit at 288G, we demonstrate a 331 μs
two-ion quantum logic gates, with 4.9(11) × 10−3 logic error probability.
This is below the 1% error threshold required for quantum error
correction and represents a ∼ 10× gate time reduction when compared
to previously demonstrated near field gradient driven microwave gates
below the 1% error probability threshold. Additionally, two faster gates
were demonstrated without the use of dynamical decoupling. Respectively,
these two gates had gate operation durations of 216.8 μs & 153.8 μs
and measured gate error probabilities of 8.5(20)×10−3 & 9.8(21)×10−3.
Further, we develop a method for rapid calculation of ion transport operations.
We successfully demonstrate ion transport as well as crystal
splitting and merging operations within two different ion traps using the
waveforms calculated by this ion transport toolbox.
gradient driven, Mølmer-Sørensen style, two-ion quantum logic
gates, which suppresses errors from both fluctuations in the qubit frequency
and imperfection in the decoupling drive itself. Using a microwaveintegrated
surface-trap which is operated cryogenically at ∼ 25K and a
magnetically insensitive 43Ca+ qubit at 288G, we demonstrate a 331 μs
two-ion quantum logic gates, with 4.9(11) × 10−3 logic error probability.
This is below the 1% error threshold required for quantum error
correction and represents a ∼ 10× gate time reduction when compared
to previously demonstrated near field gradient driven microwave gates
below the 1% error probability threshold. Additionally, two faster gates
were demonstrated without the use of dynamical decoupling. Respectively,
these two gates had gate operation durations of 216.8 μs & 153.8 μs
and measured gate error probabilities of 8.5(20)×10−3 & 9.8(21)×10−3.
Further, we develop a method for rapid calculation of ion transport operations.
We successfully demonstrate ion transport as well as crystal
splitting and merging operations within two different ion traps using the
waveforms calculated by this ion transport toolbox.