New Delhi: Scientists at the Raman Research Institute (RRI) have indigenously built an experimental facility to simultaneously cool and trap a large number of sodium and potassium atoms near absolute zero temperatures using laser light and magnetic fields.
With this, RRI, an autonomous institute funded by the Department of Science and Technology, Government of India, has joined the handful of laboratories globally to demonstrate such efficient simultaneous production of a mixture of two species of ultra-cold neutral atoms with inter-species interactions control. The results from this experiment can deepen the knowledge required for developing quantum technologies such as quantum computing, quantum sensing and metrology – all of which are the frontier areas of research.
Built over a period of five years, this specialised experimental facility comprises four interconnected ultra-high vacuum chambers, where atoms are trapped and cooled under a pressure to the tune of 10-11 millibar (equal to 14 orders lower than the normal atmospheric pressure). There are multiple intricate Laser systems, optical arrangements and high-resolution detections systems. Using techniques of flashing light onto the atoms, the researchers said that it was possible to manipulate properties of atoms and use it for taking various measurements that are fundamentally quantum mechanical in nature.
“Using a combination of light and magnetic field, we attempted to cool and trap a large number of sodium and potassium atoms from their mixture at near absolute zero temperature (in micro Kelvin). As the behaviour of atoms is different at such low temperatures in comparison to the atoms at room temperatures, we wanted to understand their quantum co-relations,” said Saptarishi Chaudhuri from the Quantum Mixtures Laboratory (QuMix), who led the latest experimental research.
“The advantage of the experiment setup is that the properties of these atoms are highly controllable. We can swiftly change many parameters without the need to produce newer samples, as is the case in most condensed matter system experiments,” explained Sanjukta Roy, co-author of the study published in the journal AIP Advances, where it has bagged the distinction of being Editor’s Pick article.
According to Sagar Sutradhar, a final-year PhD student and article’s lead author, the experiment setup includes another trap at the pre-cooling stage known as a cold atomic beam.
“It is based on the idea of two-dimensional magneto-optical trapping of atoms. This vital intervention was introduced to first cool the atoms and later push them into the main experimental setup,” said Sutradhar, who designed, implemented and characterised the performance of the system.
