Scientists show quantum interferences in atomic medium can store light

New Delhi: Scientists at the Raman Research Institute (RRI), an autonomous institute of the Department of Science and Technology (DST), have obtained a suitable optical response in an atomic medium that can be used to store light for a significant amount of time. This can help facilitate designing applications for several quantum protocols for high-precision quantum sensors, they said in a paper published in the journal Physica Scripta.

The team in collaboration with scientists from the TIFR Hyderabad used thermal Potassium and subjected the atoms to two laser lights to create quantum interferences in the atomic medium. The quantum coherence inside this atomic medium was created using the control light, which is also a laser. These probe and control lights were derived from extremely stabilised laser sources to perform the experiments using Potassium atoms.

“The innovative nature of this work lies in the use of Potassium atoms for performing Electromagnetically Induced Transparency (EIT) studies by coherent medium,” said lead author Gourab Pal, a doctoral student at the Quantum Mixtures (QuMix) lab at the RRI. The EIT -- quantum interference phenomenon -- dramatically modifies the optical response in an atomic medium. The team searched for the probe light response after it passed through an atomic coherent medium. The photons of light beams are stored inside the atomic media. When the coherence is established in the atomic media, the light information is transferred from photons to atoms. After some time, this process reverts, the researchers explained in the paper. They noted that with India fast advancing its research and development efforts in the field of quantum technologies, the ability to store light for a significant amount of time will help in multiple, futuristic quantum protocols, including quantum memory and quantum communication.