Realizing a Long-Lived Bosonic Code Using a Bit-Flip-Protected Control Qubit

Shantanu Jha | Shoumik Chowdhury | Max Hays | Miuko Tanaka | Jeff Grover | Simon Gustavsson | William D. Oliver

Bosonic encodings possess remarkable potential towards the hardware-efficient quantum error correction (QEC) necessary for universal and scalable quantum information processing. Existing experimental demonstrations of bosonic QEC codes in superconducting cavities have been dominantly limited by bit flip errors in the control qubit, which is typically a transmon with a ~100 μs T₁ lifetime. Here, we propose to instead utilize the several millisecond lifetime of a heavy fluxonium control qubit to demonstrate the creation, autonomous stabilization and fast control of Gottesman, Kitaev and Preskill (GKP) code qubits. We expect that this strongly coupled cavity-fluxonium platform will be used to demonstrate bosonic GKP qubits with unprecedented lifetimes an order of magnitude above the break-even point.

Funding Sources: Amazon Grant (6944854) | National Science Foundation Graduate Research Fellowship under Grant No. 1745302 | MIT Irwin Mark Jacobs and Joan Klein Jacobs Presidential Fellowship