Basics, intuition, and realization in dissipative SC circuits

Gottesman, Kitaev, and Preskill proposed to encode a qubit in a remarkable wavefunction, which satisfy location and momentum constraints simultaneously. Such a state offers superior error correction, but is rather hard to achieve and stabilize. We propose a circuit architecture for a dissipatively error-corrected GKP qubit. The device consists of a high-impedance LC circuit coupled to a Josephson junction and a resistor via a controllable switch. When the switch is activated via a particular family of stepwise protocols, the resistor absorbs all noise-induced entropy, resulting in dissipative error correction of both phase and amplitude errors. Furthermore, the proposed architecture provides new implementation for gates and readout, including a protected T-gate. In my talk I’ll introduce the GKP construction and explore our proposal for its realization, as well as how non-Clifford gates can be realized in the platform.

Speaker: Gil Refael, California Institute of Technology