Sub-THz electromechanics and optomechanics

Mechanical resonators are ubiquitous in modern communication systems, serving as the frequency-selective elements that enable wireless technologies. As future 6G systems push toward terahertz frequencies, there is growing interest in developing mechanical resonators that operate at hundreds of gigahertz and beyond. Such ultrahigh-frequency resonators are also attractive for quantum science because their large energy scales greatly suppress thermal excitations, enabling quantum operation at much higher temperatures than conventional microwave-frequency mechanical devices.

In this talk, I will present our work on electromechanical and optomechanical resonators operating in the sub-terahertz regime using suspended thin-film lithium niobate. I will discuss the key challenges in exciting and detecting mechanical vibrations with nanometer-scale wavelengths and describe techniques that have enabled the first piezoelectric resonators beyond 100 GHz and operation up to 220 GHz. I will also introduce integrated optomechanical structures that couple sub-THz phonons to optical resonators, providing a powerful platform for coherent phonon control and quantum transduction. Together, these advances establish a pathway toward terahertz nanomechanical systems with exciting opportunities for both next-generation 5G/6G communications and fundamental quantum science.