Quantum states are both powerful and fragile. New frontiers for quantum technologies — for quantum computing, communication, and sensing — are emerging based on quantum superposition and entanglement, but to harness these opportunities, we will need the capability to transfer these states between light-based and matter-based encodings. I will discuss the special role that optical cavities can play as quantum interfaces, that is, as bridges between quantum light and quantum matter. We will then consider two examples of such interfaces: First, we will see how trapped ions in optical cavities can form the basis for quantum networks, enabling the distribution of quantum states over long distances. Here, I will present ongoing work on a link between two remote trapped-ion systems in Innsbruck. Second, we will examine how to prepare macroscopic quantum states of motion of levitated nanoparticles in an ion trap; in the future, such states may offer new insights into the boundary between the classical and quantum worlds.
Panopto recording: GMT20201123-200109_UW-Physics_2048x1152