Superconducting circuit optomechanics in topological lattices

Abstract

Cavity optomechanics enables controlling mechanical motion via radiation pressure interaction, and has contributed to the quantum control of engineered mechanical systems ranging from kg scale LIGO mirrors to nano-mechanical systems, enabling ground-state preparation, entanglement, squeezing of mechanical objects, position measurements at the standard quantum limit, non-reciprocal photon transport, and quantum transduction. Yet, nearly all prior schemes have employed single- or few-mode op-tomechanical systems. In contrast, novel dynamics and applications are expected when utilizing optomechanical arrays and lattices, which enable to synthesize non-trivial band structures, and have been actively studied in the field of circuit QED. Superconducting microwave optomechanical circuits are a promising platform to implement such lattices, but have been compounded by strict scaling limitations. Here, we overcome this challenge and realize superconducting circuit optomechanical lattices. We demonstrate non-trivial topological microwave modes in 1D optomechanical chains realizing the canonical Su-Schrieffer-Heeger (SSH) model. Furthermore, we realize the strained graphene model in a 2D optomechanical honeycomb lattice. Exploiting the embedded optomechanical interaction, we show that it is possible to directly measure the mode functions of the bulk modes, as well as the topologically protected edge states, without using any local probe or inducing perturbation. This enables us to reconstruct the full underlying lattice Hamiltonian. Such optomechanical lattices, accompanied by the measurement techniques introduced, offers an avenue to explore out of equilibrium physics in optomechanical lattices such as collective, quantum many-body, and quench dynamics, topological properties and more broadly, emergent nonlinear dynamics in complex optomechanical systems with a large number of degrees of freedoms.Comment: Updated version with a comprehensive discussion on strained graphene mode