From smartphones to quantum computers, modern technology depends on moving information quickly and efficiently. Now, scientists have found a way to control vibrations at gigahertz (GHz) speeds—inside microscopic drumhead structures—to serve as ultra-fast bridges between mechanical, microwave and optical signals.
Gigahertz (GHz) resonances and oscillations are very important carriers of information and energy, which are key to the functions of many information processing chips and systems. Nowadays, researchers have found a way to harness GHz vibrations—on the order of billion cycles per second—in highly miniature and ultra‑light drumhead resonators, with diameters on the order of one-tenth of that of human hair, and as thin as a few molecules. These high-speed oscillations are the invisible highways that translate signals between mechanical, microwave, and optical realms.
Traditionally, creating such GHz vibrations often required excitation of bulk or surface acoustic modes in much larger structures of special crystalline materials. The breakthrough promises to bring high quality-factor (high-Q) GHz modes in ultrasmall and ultralight resonators made of atomic layers, for the first time.
In a paper released today in Science Advances, Philip Feng, Ph.D., at the University of Florida and his co-authors demonstrated that tiny drumheads made of graphene and molybdenum disulfide (MoS₂), both hallmarks of 2D crystals widely used in emerging semiconductors, optoelectronics, and energy technologies, can sustain these fast oscillations with impressively high-Qs, even at room temperature.
These findings move tiny 2D resonant transducers into a new frequency regime, opening doors for low-power signal processing, sensitive sensing, and even quantum-level communication, all while keeping device footprints minuscule.
In the new report, Feng, the Rhines Endowed Professor in Quantum Engineering in Department of Electrical and Computer Engineering and also a Graduate Professor in Physics at UF, and his colleagues show that few-layer graphene resonators exhibit multimode resonances up to ~1.03 GHz with Qs reaching ~4500, while multilayer MoS₂ devices achieve frequencies up to ~1.09 GHz with Qs as high as ~5400, all without any cryogenic cooling. These numbers set the new records for any nanoelectromechanical systems made of two-dimensional (2D) van der Waals materials operating at normal room temperatures, hinting at ultra-light, ultralow-power devices that could act as high-speed resonant sensors or GHz frequency-selecting, timing, and signal processing elements.
These ultra‑thin devices swing like miniature drumheads, but their motion is so rapid that it completes billions of cycles every second, and the movement is only a few picometers—one trillionth of a meter—across the surface.
Because their vibrations are so delicate, the team can’t set them “on” with a drumstick. Instead, the team uses a very finely tuned laser spot that gently nudges the membrane and then “listens” with a high-precision and wide-bandwidth laser‑interferometry system, one of the most sensitive ways to measure such tiny displacements at GHz frequencies. This lets the researchers both drive and read the striking, fast vibrations of these atom‑scale resonators, Feng added.
“The multimode GHz operations with picometer- or femtometer-level vibrational displacement detection, plus record-high values of measured f×Q products (a figure-of-merit for researchers to conveniently evaluate and compare various resonators made of different materials and with different geometries and fabrication processes) – these findings are exciting and encouraging,” Feng said. “They enable us to enter regimes to probe new device physics and functions. This work also points toward advanced sensing modalities and potential applications in resonant signal processing and quantum transduction with optomechanics, by interfacing and coupling such GHz modes with different species of quantum information carriers, such as color centers in 2D materials, or superconducting qubits.”
While the breakthrough proves that atom-layer 2D nanomechanical resonators can generate gigahertz-scale vibrations at room temperature, more engineering work is still needed to turn these transducers into practical, system-level tools. The demonstration marks an encouraging advance for both basic research into ultrafast mechanics and for future device applications that could harness the unusual properties of 2D materials.