Disentanglement of physical mechanisms for driving and detection in piezoelectric nanoelectromechanical systems

Abstract

Nanoelectromechanical systems based on (Al,Ga)As/GaAs heterostructures with a two-dimensional electron gas can rely on both piezoelectric and electrostatic driving and detection. While this multifunctionality may be beneficial, disentanglement of these two physical mechanisms is important. In a multi-mode nanoelectromechanical system, we experimentally discern the electrostatic and piezoelectric effects in various configurations. A well-controlled system relying entirely on the electrostatic effect is demonstrated, where a field-effect transistor reads out the oscillations of its cantilevered side gate. We show that, apart from the two mentioned mechanisms, an additional time-delayed driving force arises due to the generation of bulk acoustic waves in the entire chip.