Toward realization of quantum LDPC devices

The introduction of quantum low-density-parity-check (qLDPC) [1] codes promises to significantly decrease the overhead associated with quantum error correction. This decrease, however, comes at the expense of device complexity. qLDPC devices require connectivity beyond 2D and often require this connectivity to be long-range. In this talk, I will review the progress made by the IBM team in realizing the necessary elements of this architecture, such as a demonstration of high connectivity, long-distance couplers, couplers that break out of the plane, and the ability to actively reset qubits. I will review how these elements will be integrated into the Loon quantum chip, the first qLDPC prototype.

[S. Bravi et al, Nature 627, 778 (2024)]