Warwick and NRC propose phononic links to connect distant qubits on a chip

University of Warwick and NRC Canada researchers propose Quantum Phononic Links, an architecture that would use sound-like vibrations in engineered semiconductor material to carry quantum information between distant qubits on a single chip. Published in APL Quantum, the concept targets long-range connectivity limits on leading quantum chips that typically let only neighboring qubits talk directly. The team focuses on compressively strained germanium on silicon, where qubits are sensitive to controlled gigahertz phonons that could act as an on-chip quantum bus across distances up to a full 300 mm wafer. Unlike microwave links or externally generated surface acoustic waves that need extra hardware, the phononic links would be built into the host semiconductor and stay compatible with established fabrication. Phys.org covered the paper (DOI 10.1063/5.0332643), quoting Warwick's Maksym Myronov on using phonons as a quantum bus for distant hole spin qubits.