  We report the observation of both resonant quantum tunneling of magnetization
(RQTM) and resonant quantum magnetodielectric (RQMD) effect in the perovskite
multiferroic metal-organic framework [CH3NH3]Co(HCOO)3. An intrinsic magnetic
phase separation emerges at low temperatures due to hydrogen-bond-modified long
range super-exchange interaction, leading to the coexistence of canted
antiferromagnetic order and single-ion magnet. Subsequently, a stair-shaped
magnetic hysteresis loop along the [101] direction characterizing the RQTM
appears below the magnetic blocking temperature. More interestingly, the
magnetic field dependence of dielectric permittivity exhibits pronounced
negative peaks at the critical fields corresponding to the RQTM, a phenomenon
termed the RQMD effect which enables electrical detection of the RQTM. These
intriguing properties make the multiferroic metal-organic framework a promising
candidate for solid-state quantum computing.
