A new state of matter created

These atoms are held together by a weak bond and is created at very cold temperatures

March 07, 2018 05:20 pm | Updated March 08, 2018 05:37 pm IST

The electron (blue) orbits the nucleus (red) - and its orbit encloses many other atoms of the Bose-Einstein-condensate (green).

The electron (blue) orbits the nucleus (red) - and its orbit encloses many other atoms of the Bose-Einstein-condensate (green).

An international team of physicists have successfully created a “giant atom” and filled it with ordinary atoms, creating a new state of matter termed “Rydberg polarons”. These atoms are held together by a weak bond and is created at very cold temperatures.

“For us, this new, weakly bound state of matter is an exciting new possibility of investigating the physics of ultracold atoms,” says Joachim Burgdörfer, theoretical physicist from TU Wein and one of the authors of the paper published in Physical Review Letters .

Dr.Ganesh Ramachandran from the Condensed Matter Group at Institute of Mathematical Sciences, Chennai explains the new Rydberg polarons

How was the new polaron created?

This is an intricate experiment that builds upon several advances that were achieved over the past two decades.

It uses ideas from two different fields: Bose Einstein Condensation and Rydberg atoms.

A BEC (Bose Einstein Condensate) is a liquid-like state of matter that occurs at very low temperatures. A BEC can be perturbed to create excitations which are akin to ripples on a lake. Here, the authors have used a BEC of strontium atoms.

Electrons in an atom move in orbits around the nucleus. A ‘Rydberg atom’ is an atom in which an electron has been kicked out to a very large orbit. These have interesting properties and have been studied for a long time.

In this work, the authors used laser light on a BEC of strontium atoms so that it impinges on one strontium atom at a time. This excites an electron into a large orbit, forming a Rydberg atom. This orbit is large enough to encircle many other strontium atoms inside it.

As the electron moves around many strontium atoms, it generates ripples of the BEC. The Rydberg atom becomes inextricably mixed with these ripples and forms a new super-atom called a ‘Rydberg polaron’.

What will be the use of these Rydberg polarons?

A particularly interesting implication is for cosmology. Our universe is believed to be filled with a mysterious ‘dark matter’ which exerts a gravitational force on other matter.

Some theories of dark matter postulate that it is a cosmic Bose Einstein Condensate, perhaps composed of an as-yet-unknown type of particle. If we are indeed living in an invisible all pervading Bose Einstein Condensate, this experiment can suggest ways to detect it.

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.