Since the turn of the millennium, micro- and nanoscale superconducting circuits have evolved from a playground for solid-state physicists dreaming about quantum mechanics into a serious candidate for quantum information processing, simulation, communication and sensing. After an introduction into the fundamentals and state of the art of the field, I present an overview over the related activities at the WMI. Specifically, I discuss two recent experiments. In one of them, we use the flexibility of superconducting circuits to create an artificial atom with a dipole and a quadrupole moment and some kind of artificial orbital momentum. Using a pair of antennas for excitation, we engineer the interaction parity and observe the corresponding selection rules. In the second work, we employ the multimode structure of a highly-coherent 3D cavity architecture to implement a compact and scalable quantum memory.
We acknowledge financial support from the German Research Foundation through FE 1564/1-1 and the Excellence Cluster Nanosystems Initiative Munich (NIM), the doctorate program ExQM of the Elite Network of Bavaria, and the International Max Planck Research School ”Quantum Science and Technology“.
