The ultrathin metasurface produces a network of entangled quantum photons

The ultrathin metasurface produces a network of entangled quantum photons

Scientists at Sandia National Laboratories and the Max Planck Institute have developed a way to produce a lattice of quantum entangled photons using a much simpler setup than usual. The key is a precisely patterned surface 100 times thinner than paper that could replace a room full of optical equipment.

Quantum entanglement is the bizarre-sounding phenomenon where two particles can become so entangled that manipulating one will instantly affect its partner, no matter how far away they are. This forms the basis for emerging technologies such as quantum computing and quantum encryption.

The problem is that generating bunches of entangled photons can be difficult and is usually done with large arrays of lasers, specialized crystals, and other optical equipment. But the Sandia and Max Planck team has a much simpler setup—a metasurface.

These devices act like lenses, manipulating the light that passes through in a very controlled way. But instead of doing this using their curvature and thickness, the metasurfaces have been precisely etched with nanoscale structures to change light depending on the task at hand, including trapping atoms, capturing sharper colors in images, and even producing holograms. Best of all, metasurfaces can accomplish these feats in devices much smaller than previous technology.

The team’s new metasurface is illuminated with green laser light

Craig Fritz

For this study, the team’s metasurface took the form of an ultrathin sheet of glass coated with nanostructures made from the semiconductor material gallium arsenide. When a laser is transmitted through the metasurface, some of the photons that come out the other side do so in entangled pairs. And not just one pair at a time, but a whole network of entangled photons. This, the team says, normally requires an entire lab full of equipment to accomplish.

“It’s quite complicated and somewhat intractable when this multiple entanglement needs more than two or three pairs,” said Igal Brener, the study’s lead researcher. “These nonlinear metasurfaces essentially accomplish this task in a single sample, when before it would have required incredibly complex optical setups.”

The ability to induce quantum entanglement in groups of photons simultaneously could have a wide range of applications for quantum computing, encryption, communication and optics. Before that happens, the team says there is still work to be done to improve the efficiency of the metasurface.

The research was published in the journal Science.

Source: Sandia Labs

Leave a Comment

Your email address will not be published.