  Manipulating carrier density through gate effects, both in electrostatic
charge storage and electrochemical intercalation mode, offers powerful control
over material properties, although commonly restricted to ultra-thin films or
van der Waals materials. Here we demonstrate the application of gate-driven
carrier modulation in the microdevice of magnetic Weyl semimetal Co3Sn2S2,
fabricated from a bulk single crystal via focused ion beam (FIB). We discovered
a Li-intercalated phase LixCo3Sn2S2 featuring electron doping exceeding 5*1021
cm-3, resulting in the Fermi energy shift of 200 meV. The carrier density
dependent anomalous Hall conductivity shows fair agreement with density
functional theory (DFT) calculation, which also predicts intercalated Li+ ion
stabilization within the anion layer while maintaining the kagome-lattice
intact. This likely explains the observed rigid band behavior and constant
Curie temperature, contrasting with magnetic site substitution experiments. Our
findings suggest ionic gating on FIB devices broadens the scope of gate-tuning
in quantum materials.
