  Single-atom magnetism switching is a key technique towards the ultimate data
storage density of computer hard disks and has been conceptually realized by
leveraging the spin bistability of a magnetic atom under a scanning tunnelling
microscope. However, it has rarely been applied to solid-state transistors, an
advancement that would be highly desirable for enabling various applications.
Here, we demonstrate realization of the electrically controlled Zeeman effect
in Dy@C84 single-molecule transistors, thus revealing a transition in the
magnetic moment from 3.8 {\mu}B to 5.1 {\mu}B for the ground-state GN at an
electric field strength of 3-10 MV/cm. The consequent magnetoresistance
significantly increases from 600% to 1100% at the resonant tunneling point.
Density functional theory calculations further corroborate our realization of
nonvolatile switching of single-atom magnetism, and the switching stability
emanates from an energy barrier of 92 meV for atomic relaxation. These results
highlight the potential of using endohedral metallofullerenes for
high-temperature, high-stability, high-speed, and compact single-atom magnetic
data storage.
