Persistent and Reversible Frequency Tuning in Graphene/Hexagonal Boron-Nitride Nanomechanical Resonators

Persistent and reversible methods for tuning the resonance frequency of a nanomechanical resonator are essential for fields ranging from quantum information to ultra-sensitive force and mass sensing. However, reliable methods to achieve this tuning have been difficult to realize.

Here, we demonstrate that the resonance frequency of nanomechanical resonators can be persistently and reversibly tuned using photoelectric doping[1]. We demonstrate this effect in drumheads made from heterostructures of hexagonal boron-nitride (h-BN) and graphene. However, this technique could potentially be extended to electromechanical resonators made from any material that can be photoelectrically doped. We observe tuning that is robust over weeks, can occur at rates as fast as ~1 GHz/s, and has a tuning range of greater than 250%.This could enable future applications which need large numbers of individually tunable nanomechanical elements, such as chip-scale optomechanical circuits.

[1] L. Ju et al., “Photoinduced doping in heterostructures of graphene and boron nitride,” Nat. Nanotechnol., vol. 9, no. 5, pp. 348–352, 2014.