A group of researchers from Caltech has made a groundbreaking discovery in the world of quantum effects. They have found a new phenomenon called “collectively induced transparency” (CIT), which causes groups of ytterbium atoms to stop reflecting light at specific frequencies. By confining the atoms in an optical cavity and shining a laser on them, they discovered a transparency window where the light passes through the cavity without any obstruction.
The team found that the transparency window was due to interactions in the cavity between groups of atoms and light. The phenomenon is similar to destructive interference, where waves from multiple sources can cancel each other out. The groups of atoms absorb and re-emit light, resulting in the reflection of the laser’s light. However, at the CIT frequency, there is a balance created by the re-emitted light from each of the atoms in a group, causing a drop in reflection.
The researchers also observed that the collection of atoms can absorb and emit light from the laser either much faster or much slower than a single atom, depending on the intensity of the laser. These processes, called superradiance and subradiance, and their underlying physics are still not well understood due to the large number of interacting quantum particles.
The research primarily expands our understanding of quantum effects, but it has the potential to pave the way for more efficient quantum memories in which information is stored in an ensemble of strongly coupled atoms. The team hopes that their experimental systems will provide important insights into developing future connections between quantum computers.