Nanofabrication of a silicon chip with all quantum info processor

Prof. Hong Tang has devised a process of nanofabrication to create a silicon chip that contains all the components needed for a quantum information processor

"We can make a lot of these nanodevices easily by copying our design hundreds or thousands of times, without much additional effort or cost," said Carsten Schuck, post-doctoral researcher and lead author of the paper. "It’s similar to what people in the semiconductor industry do, who developed the technology to make billions of transistors."

The two essential requirements for a scalable quantum information processor are quantum interference (in which a photon – able to be in more than one place at a time – crosses its own path) and single-photon detectors. The chip that the researchers designed contains a nanophotonic waveguide, which can guide light into small spaces and to wherever is needed on the chip. It also has a directional coupler that can split a light beam into two identical beams, or conversely, combine two beams into one output. Schuck compares his system to state-of-the-art experimental setups consisting of hundreds of bulky optical components to control a quantum system.

Nature Communications – Quantum interference in heterogeneous superconducting-photonic circuits on a silicon chip