A magneto-optic modulator could facilitate the development of next-generation superconductor-based computers

Researchers at University of California Santa Barbara, Raytheon BBN Technologies, University of Cagliari, Microsoft Research, and the Tokyo Institute of Technology have recently developed a magneto-optic modulator—a device that control the properties of a light beam through a . This device, introduced in a paper published in Nature Electronics, could contribute to the implementation of large-scale electronics and computers based on superconductors.

"We are working on a new technology that can speed up high-performance supercomputers and quantum computers based on superconductor technology," Paolo Pintus, the researcher who led the study, told TechXplore. "Superconductors work properly only at low temperatures, generally just above absolute zero (-273.15° Celsius). Because of this, circuits made of these materials must be kept inside a dedicated refrigerator."

Circuits made of superconductors are typically connected to their external surroundings using metal cables. These cables have a limited communication speed and can transfer heat into a cold circuit.

A promising alternative would be to use optical fibers, thin and flexible glass wires that can convey light signals and are currently used to bring internet data over long distances. These fibers offer two main advantages over metal cables: they can transmit 1,000 times more data within the same period of time without transferring heat, since glass is a good thermal insulator.

"As part of our work, we designed and fabricated a device (known as '') that converts information carried by an in an electromagnet into light," Pintus explained. "This is thanks to a called 'magneto-optic effect.' This light can travel through an and carry information out of the cold environment, without altering the functionality of the cold circuit."

Credit: Pintus et al.

Credit: Pintus et al.

Electricity flowing through a metal coil generates electric (purple) and magnetic (faint green) fields. This changes the properties of the substrate, which tunes the resonance ring (red) to different frequencies. The whole setup enables the scientists to convert a continuous beam of light (red on left) into pulses that can carry data through a fiber-optic cable. Credit: Brian Long, Senior Artist, Marketing and Communications of the University of California Santa Barbara