IQIM Postdoctoral and Graduate Student Seminar

Abstract: **Note room change - this week we are in Keck 142

Recent advancements in the ability to create and manipulate superconducting quantum systems have created an exciting opportunity to construct quantum materials that are tailored to host rich interactions. The extensive microwave toolbox and comparatively large sizes of microwave photons enable targeted Hamiltonians to be built from the ground up, artificial atom by atom. I will discuss today how to create both magnetic field and particle-particle interactions for photons inhabiting a two-dimensional lattice of 3D superconducting microwave cavities. The combination of both these interactions enables exploration of the Harper-Hubbard model which is anticipated to support fractional Chern insulating many-body phases. The magnetic field is created by coupling lattice sites to magnon modes of ferrimagnetic crystals put inside the cavities. This effective magnetic field results in energy bands where the only modes of the lattice live on the edge of the material and propagate in one direction, topologically protected against back-scattering. Next, effective onsite particle-particle interactions are implemented by coupling transmon qubits to lattice sites. I will show recent results in coupling a single transmon to the edge of the lattice, demonstrating a system that can be used to explore chiral quantum electrodynamics. Finally, I will discuss the path towards coupling transmons to each site of the lattice in order to achieve the onsite interactions necessary to create a fractional quantum Hall system.