Researchers create superconducting germanium semiconductor material using standard chip-making techniques - prototype demonstrates millions of superconducting junctions on a 2-inch wafer

An image depicting Josephson junction structures: quantum devices made of two superconductors and a thin non-superconducting barrier.

Researchers at NYU and the University of Queensland have demonstrated superconductivity in gallium-doped epitaxial germanium, fabricated using industry-standard semiconductor tools. The new material switches to a superconducting state below 3.5 Kelvin and supports dense, wafer-scale Josephson junction arrays, an important building block for quantum and cryogenic RF circuits.

The team’s prototype demonstrates millions of superconducting junctions integrated on a single 2-inch wafer. Junctions were lithographically defined and electrically characterized at low temperatures, confirming both superconducting behavior and practical current densities for device integration.