  Neutral atom array serves as an ideal platform to study the quantum logic
gates, where intense efforts have been devoted to improve the two-qubit gate
fidelity. We report our recent findings in constructing a different type of
two-qubit controlled-PHASE quantum gate protocol with neutral atoms enabled by
Rydberg blockade, which aims at both robustness and high-fidelity. It relies
upon modulated driving pulse with specially tailored smooth waveform to gain
appropriate phase accumulations for quantum gates. The major features include
finishing gate operation within a single pulse, not necessarily requiring
individual site addressing, not sensitive to the exact value of blockade shift
while suppressing population leakage error and rotation error. We anticipate
its fidelity to be reasonably high under realistic considerations for errors
such as atomic motion, laser power fluctuation, power imbalance, spontaneous
emission and so on. Moreover, we hope that such type of protocol may inspire
future improvements in quantum gate designs for other categories of qubit
platforms and new applications in other areas of quantum optimal control.
