Scientists successfully demonstrated quantum interference among several single photons

A leap forward in optical quantum computing.


Photon interaction is a fundamental phenomenon in quantum optics and a key to optical quantum computing. It involves harnessing the properties of light, such as its wave-particle duality, to induce interference patterns, enabling the encoding and processing of quantum information.

Traditional multiphoton experiments use spatial encoding. In this process, photons are controlled in different spatial paths to trigger interference. However, these experiments demand complex setups with several components, making them resource-intensive and challenging to scale.

In a new study, an international collaboration of researchers has successfully demonstrated quantum interference among several single photons using a novel resource-efficient platform.

For this study, researchers chose an approach based on temporal encoding. This technique manipulates photons’ time domain rather than their spatial statistics.

To realize the approach, they developed an innovative architecture using an optical fiber loop. This allows them to use the same optical components repeatedly, allowing efficient multiphoton interference with minimal physical resources.

First author Lorenzo Carosini explains“In our experiment, we observed quantum interference among up to eight photons, surpassing the scale of most existing experiments. Thanks to the versatility of our approach, the interference pattern can be reconfigured, and the size of the experiment can be scaled without changing the optical setup.”

The outcomes show that the implemented architecture is far more resource-efficient than conventional spatial-encoding techniques, opening the door for more widely available and scalable quantum technologies.

Journal Reference:

  1. Lorenzo Carosini, Virginia Oddi, Francesco Giorgino et al. Programmable multiphoton quantum interference in a single spatial mode. Science Advances. DOI: 10.1126/sciadv.adj0993


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