An interdisciplinary team of researchers led by Prof. Alexander Szameit at the University of Rostock, in collaboration with the Albert-Ludwigs-University of Freiburg, has achieved groundbreaking advancements in stabilizing photon interference. These findings, published in the prestigious journal Science, are considered a major step forward in the development of new optical quantum technologies, including quantum computers.
The challenge in using light for quantum computing lies in the fact that even the smallest errors in the manufacturing of optical chips can significantly affect the stability of light transmission. However, the Rostock and Freiburg team demonstrated that light can propagate through optical waveguides with topological protection, meaning the light waves remain stable even when there are slight manufacturing imperfections. This breakthrough promises to make quantum technologies more robust and reliable.
The process uses what is known as the Hong-Ou-Mandel interference, a phenomenon where two photons interfere with each other, exchanging quantum information. This interference is stabilized by a synthetic magnetic flux difference in the waveguides, allowing for error-resilient quantum gates.
Scientific Significance
This discovery has the potential to revolutionize future applications in quantum communication and computing. The ability to make quantum computers more resistant to fabrication errors addresses a key challenge in scaling up this technology.
Citation: Max Ehrhardt et al., "Topological Hong-Ou-Mandel interference," Science, 2024. DOI: 10.1126/science.ado8192