  Advances in research such as quantum information and quantum chemistry
require subtle methods for trapping particles (including ions, neutral atoms,
molecules, etc.). Here we propose a hybrid ion trapping method by combining a
Paul trap with optical tweezers. The trap combines the advances of the
deep-potential feature for the Paul trap and the micromotion-free feature for
the optical dipole trap. By modulating the optical-dipole trap synchronously
with the radio frequency voltage of the Paul trap, the alternating electrical
force in the trap center is fully counteracted, and the micromotion temperature
of a cold trapped ion can reach the order of nK while the trap depth is beyond
300K. These features will enable cold collisions between an ion and an atom in
the $s$-wave regime and stably trap the produced molecular ion in the cold
hybrid system. This will provide a unique platform for probing the interactions
between the ions and the surrounding neutral particles and enable the
investigation of new reaction pathways and reaction products in the cold
regime.
