Autonomous Fock state stabilization by reservoir engineering*

Quantum computing requires the ability to create and maintain quantum states. However, due to persistent coupling to the environment a quantum state suffers from decoherence. In order to fight decoherence physicists have come up with different approaches such as circuit based quantum error correction and reservoir engineering. Here we present a reservoir engineering scheme which autonomously stabilizes Fock states in a superconducting waveguide cavity. We will discuss how a vertical transmon qubit is used as a nonlinear coupler between two superconducting waveguide cavities. This nonlinear coupling creates a direct, strong-dispersive interaction between the two cavities. We utilize this interaction to autonomously stabilize Fock states by applying classical continuous wave drives. We present preliminary experimental results.