A water-based molecular flip-flop

The flip-flop, which has been widely used in digital circuits, has two stable states and can be used to store state information. Because traditional flip-flops based on digital circuits suffer from a barrier to higher performance, it is necessary to explore some new alternative devices. For this purpose, we utilize molecular dynamics simulations to design a molecular flip-flop, which contains one water molecule confined within a single-walled carbon nanotube. Its two states can be switched within 0.5 ps (2000 GHz), and its state information can be exported by the charged atomic-force microscope force probes. The mechanism of the flip-flop depends on the behavior of a water molecule in a nonuniform electric field. In particular, a water molecule always moves toward the location of lowest electric energy in a nonuniform electric field generated by point charges. The resulting flip-flop could be utilized for designing nanoscale devices.