The control of the charge- and spin state of single molecules is key for the design of molecular electronic and spintronic devices. For switching the spin or magnetic state of molecules two principles have been used in the past: (1) atoms or small molecules were added to and removed from the host molecule or (2) by modifying the shape of molecules which can exist in more than one configuration. The realization of both methods is rather difficult. In cooperation with theorists around Prof. Giorgio Sangiovanni (TP I), in a recent publication our group presented an alternative way to achieve multiple and reversibly switchable spin states in a single molecules. These results show that a bistable molecular state can be achieved by positioning single manganese phthalocyanine (MnPc) molecule on top of an antiphase boundary of the (3×3)-reconstructed surface alloy of bismuth on Ag(111). In this environment we can switch single molecules between a high- and a low-spin state by using the electric field of a sharp STM tip. The result has been published in npj Quantum Materials.
