Ultra-sensitive charge detection and latch memory using MoS2-nanoresonator-based bifurcation amplifiers

Bifurcation amplifiers are known for their extremely high sensitivity to weak input signals. We implement a bifurcation amplifier by harnessing the Duffing nonlinearity in a parametrically excited MoS₂ nano-electromechanical system. We utilize the ultra-sensitive switching response between the two states of the bifurcation amplifier to detect as well as register charge-fluctuation events. We demonstrate open-loop real-time detection of ultra-low electrical charge perturbations of magnitude <10 e at room temperature. Furthermore, we show latching of the resonator onto one of the two states in response to short-lived charge fluctuations. These charge detectors offer advantages of room-temperature operation and tunable operation in the radio frequency regime, which could open several possibilities in quantum sensing.