ISTA Physicists Demonstrate Optical Readout of Superconducting Qubits

Researchers at the Institute of Science and Technology Austria (ISTA), led by Professor Johannes Fink, have demonstrated a fully optical readout of superconducting qubits utilising an electro-optic transducer, a device converting between electrical and optical signals. This achievement, reported earlier in 2025, addresses a key limitation in scaling quantum computing and networking technologies, which currently rely on superconducting qubits operating at ultracold temperatures with electrical signals. The European Research Council has awarded Professor Fink a 150,000 euro Proof of Concept grant to further develop this technology towards a future optics-based quantum internet capable of long-distance, room-temperature operation. This work is predicated on the potential for quantum computers to surpass classical computers in solving specific problems, contingent upon overcoming existing technological hurdles.

The European Research Council has awarded Johannes Fink a Proof of Concept grant of 150,000 euros to support the commercialisation of technology for a future optics-based quantum internet. Large-scale quantum computation is anticipated to rely on distributed quantum computing and the development of a quantum internet, necessitating advancements in current technologies. Current approaches utilise superconducting qubits, which rely on electrical signals at ultracold temperatures, presenting challenges for establishing room-temperature connections.

Physicists at the Institute of Science and Technology Austria (ISTA) have demonstrated a fully optical readout of superconducting qubits using an electro-optic transducer – a device that converts between electrical and optical signals. This achievement addresses a critical limitation in the scaling of quantum computing and networking technologies, as superconducting qubits currently require substantial cooling and complex machinery to operate with electrical signals. The development of optical frequencies is considered necessary for any future quantum network, owing to their capacity to travel long distances at room temperature.

Earlier this year, researchers from Professor Johannes Fink’s group at ISTA achieved a fully optical readout of superconducting qubits, representing a step towards realising an optical quantum internet. Superconducting qubits are fabricated by cooling tiny electrical circuits to ultracold temperatures, eliminating electrical resistance and enabling indefinite current flow. Quantum computers hold the promise of outperforming classical computers in solving specific problems, but remain research endeavours due to existing technological hurdles.