a. Key Laboratory of
Materials Physics, Institute of Solid State Physics, Chinese Academy of
Sciences, Hefei 230031, China
b. University of Science and Technology of China, Hefei, China
c. Beijing Computational Science Research Center, Beijing 100084, China
Abstract: To make memory devices based on an individual single-molecule magnet
work far above the blocking temperature, we propose a new route, where
the information is contained in the charge state of the molecule, and it
works through charging and discharging the molecule by applying gate
voltages. Here, a model device built on a single-molecule magnet, Fe4, is taken as an example to exhibit the validity of our proposed route. Ab initio
calculations show that the two different charge states with a
moderately large energy shift of 1.2 eV are responsible for the low and
high conductances in this device: one corresponds to the neutral state
of the molecule, and the other to its anionic state. Moreover, the
transition from the neutral state to the anionic state is accompanied by
a giant increase of nearly two orders of magnitude in the conductance.
Additionally, the low and high conductances before and after charging
the molecule are hardly dependent on the different spin configurations
of the Fe4 molecule, which indicates that the performance of the Fe4 memory device is probably preserved even at room temperature.
