Nanomechanical coupling between microwave and optical photons

Abstract

A variety of nanomechanical systems can now operate at the quantum limit1,2,3,4, making quantum phenomena more accessible for applications and providing new opportunities for exploring the fundamentals of quantum physics. Such mechanical quantum devices offer compelling opportunities for quantum-enhanced sensing and quantum information5,6,7. Furthermore, mechanical modes provide a versatile quantum bus for coupling hybrid quantum systems, supporting a quantum-coherent connection between different physical degrees of freedom8,9,10,11,12,13. Here, we demonstrate a nanomechanical interface between optical photons and microwave electrical signals, using a piezoelectric optomechanical crystal. We achieve coherent signal transfer between itinerant microwave and optical fields by parametric electro-optical coupling using a localized phonon mode. We perform optical tomography of electrically injected mechanical states and observe coherent interactions between microwave, mechanical and optical modes, manifested as electromechanically induced optical transparency. Our on-chip approach merges integrated photonics with microwave nanomechanics and is fully compatible with superconducting quantum circuits, potentially enabling microwave-to-optical quantum state transfer, and photonic networks of superconducting quantum bits14,15,16.