← Quantum & Cryogenics
Dependency· Quantum & Cryogenics · Link
Sapphire substrates & tantalum films
diffus, United States / Japan42.09°N 71.40°W
computed criticality11/100
reading
Niobium → tantalum shift: transmon coherence > 0.3 ms (≈×2-5)
2024Fault line
Around 2021-2024, IBM, Google and Fermilab's SQMS centre showed that the native oxide of tantalum deposited on sapphire dissipates far less than that of niobium, pushing coherence times beyond 300 µs. The bottleneck shifts to niche materials: ultra-pure sapphire wafers and tantalum sputtering targets, with few and non-redundant suppliers.
Actors
IBM Research (Yorktown)
Fermilab SQMS
Sapphire/tantalum suppliers (diffuse)
Feeds 1
Superconducting qubits, IBM & GoogleQuantum & Cryogenics↗Sources