Niobium Nitride (NbN)

Superconducting Materials

High-Tc Nitride for Photon Detection & Qubits

Tc = 16 K (bulk); ~10 K thin film

Niobium Nitride (NbN)

High-Tc Nitride for Photon Detection & Qubits

Role in quantum circuits

Superconducting nanowire single-photon detectors (SNSPDs), resonators, qubit circuits

Why it matters

NbN has the highest Tc among common superconducting nitrides and is prized for

single-photon detection at near-infrared wavelengths. Its large superconducting gap makes it resistant to quasiparticle poisoning — a key decoherence mechanism in qubit circuits used in quantum networking nodes.

Key facts

• Highest Tc among common nitrides — operable at 4 K with standard cryostats

• Used in SNSPDs for quantum communication & networking links

• Large superconducting gap reduces quasiparticle poisoning

• Deposited by reactive magnetron sputtering on MgO or sapphire

• Integrated into quantum networking nodes alongside transmon qubits