LSU physicists build room-temperature gold metacrystal that sorts quantum states of light

Louisiana State University physicists created what ScienceDaily describes as the first room-temperature quantum material able to identify and transport distinct quantum states of light, in a study reported in Nature. Led by Associate Professor Omar S. Magaña-Loaiza, the team placed a thin gold layer on a glass chip and used focused ion beams to cut hundreds of tiny slits that act as meta-atoms, forming a structure thinner than a human hair. By tuning size, shape, and spacing, the material filters which quantum statistics of light may pass and routes different quantum states along separate paths without cryogenic cooling. The group calls the device a quantum statistical plasmonic metacrystal and reports quantum statistical bands analogous to electronic bands in semiconductors. Magaña-Loaiza said the crystal can distinguish quantum states that carry information and move them from one point to another without requiring cryogenic cooling. Former postdoc Chenglong You and colleagues framed the work as engineering a material nature does not supply on its own rather than searching for a natural substance. ScienceDaily said almost every prior quantum material of this kind needed near-absolute-zero cooling because heat vibrations disrupt fragile quantum effects. The LSU Quantum Photonics Group handled theory, design, nanofabrication, and testing.