A Gd@C₈₂-based single electron transistor device with ferroelectric-like switching behavior

Ferroelectricy arises from permanent dipole and has led to technology innovation in memory devices. However, maintaining ferroelectricity at nanoscale is challenging, greatly limits its application in nanoscale devices. Here we report the gate-controlled switching between two sets of single-electron characteristic stability diagrams in the electrical transport of a Gd@C₈₂-based single molecular device. It is operated in a hysteresis-like loop with a coercive gate field of up to 0.5 V/nm. The theoretical calculations attribute the two diagrams to the energy levels of two trapping states of the Gd atom in the C₈₂ cage, which possess two different permanent electrical dipole configurations. The switching thus originates from the electrical field driven dipole flipping and demonstrate the ferroelectricity at the single molecule level.