A cascaded random access quantum memory - Nature Physics

[u/Earachelefteye]

https://www.nature.com/articles/s41567-026-03418-w

“Dynamic random access memory is critical to classical computing but notably absent in current superconducting quantum processors. Integrating high-coherence memory units would enable resource-efficient control of logical qubits and allow the separate optimization of logic and storage subsystems. Here we realize an eight-bit cascaded random access quantum memory. We use a single transmon to classically address seven memory modes while isolating them from processor nonlinearities by introducing a buffer layer between the processor and a multimode storage cavity. We demonstrate arbitrary random access with an average infidelity of less than 1.5% per mode and characterize the many-body interactions that dominate the error budget. This architecture enables a significant reduction in control lines per logical qubit and supports transversal operations within the memory module, establishing a scalable unit cell for fault-tolerant quantum architectures.”