New Method Bridges Gap Between Quantum Systems

Researchers have developed a new technique for converting microwave photons to optical photons, a critical step toward building scalable quantum computing networks. The approach uses a nanoscale silicon beam vibrating at high frequency, coupled with a microwave resonator to perform the energy conversion with remarkably low noise.

The device bridges the significant energy gap between the microwave domain, where superconducting qubits operate at ultralow temperatures, and the optical domain, where photons can travel through standard fiber optic cables at room temperature. This conversion is essential for connecting distant quantum processors into a larger distributed network.

"Our method is agnostic to the exact material that the mechanical oscillator is built from," explains Dr. Alex Chen, lead researcher on the project. "We were able to build the transducer from silicon, which has been shown to have very little heating under laser illumination. This enables us to achieve the low noise levels demonstrated in this work."

The device converts microwave photons to optical photons approximately 100 times more efficiently than previous state-of-the-art systems at equivalent noise levels. The team achieved this by combining electrostatic actuation with carefully engineered mechanical resonances in the silicon nanostructure.

Graduate student Maria Lopez is also an author of the paper describing the work, which was published in a leading scientific journal. The research was supported by federal quantum computing research initiatives and national science foundations. Device fabrication was performed at the university nanofabrication facility.