Quantum Computers Take a Major Step Forward with Fiber-Optic Innovation

Quantum computing advances rapidly thanks to qubits—the building blocks of these systems. Among these, superconducting qubits promise scalability but rely on electrical signals, which pose scaling challenges.

However, physicists at the Institute of Science and Technology Austria (ISTA) have now developed a fully optical readout for superconducting qubits, as published in Nature Physics. This breakthrough paves the way for more efficient and scalable quantum computers.

Previously, quantum computing stocks surged but then stalled after Nvidia CEO Jensen Huang predicted that “very useful quantum computers” remain two decades away. Nevertheless, the race continues. In response, Professor Johannes Fink’s group at ISTA developed a method that lets qubits communicate via fiber optics, thereby reducing the need for bulky cryogenic hardware.

As co-first author Georg Arnold explains, this approach could boost qubit numbers for computation and even enable a network of superconducting quantum computers operating at room temperature.

The Challenge of Integrating Fiber Optics into Quantum Systems

Moreover, although fiber optics revolutionized telecom by offering high bandwidth and low heat dissipation, applying them to quantum systems is challenging.

Superconducting qubits require extremely low temperatures to eliminate electrical resistance, and electrical signals have low bandwidth, generate heat, and require elaborate cooling. Therefore, traditional qubit readout demands costly and complex cryogenic setups.

ISTA Team Innovates with Electro-Optic Transducer to Bridge Optical and Microwave Signals for Qubits, Reducing Errors and Costs

To overcome these issues, the ISTA team employed an electro-optic transducer to convert optical signals into microwave frequencies—signals that qubits can understand. In turn, qubits reflect a microwave signal that the transducer converts back into optical signals.

Thomas Werner, another co-first author, noted that they managed to send infrared light near the qubits without disrupting their superconductivity. Consequently, this innovation disconnects the qubits from heat-generating electrical wiring, reducing errors and lowering costs.

Furthermore, this technology could eventually allow scientists to link multiple quantum computers using optical fibers, overcoming the limitations imposed by dilution refrigerators.

While current infrastructure restricts the number of qubits, optical connections might enable simple quantum networks. Although challenges remain—such as optimizing optical power—this proof-of-concept marks a significant step toward scalable quantum computing.

Read Original Article: Scitechdaily

Read More: Scientists Uncover a New Type of Quantum State in Graphene