Rydberg Polaron

Rydberg Polaron is a very recently discovered state of matter. It is now known as 6th state of matter.

This state was predicted by theorists in 2016 at TU Wein (Vienna) and Harvard University, and is confirmed at Rice university in Houston (Texas) in 2018 by using the spectroscopic techniques.

Scientists used two fields of atomic physics to establish this state, i.e., Bose-Einstein condensate and Rydberg atoms.

Bose-Einstein condensate is 5^th state of matter that exists at very low temperature, near to absolute zero. 

Rydberg atom are those in which an atom is send to excited state. In this state, electron will be far away from the nucleus. As a result, a lot of space is left empty in which many atoms can fit. In this, many atoms are fitted in between the nucleus and the electron of other atom.

How it is made?

First, a Bose-Einstein state was created with a strontium atom. Then, using a laser, energy is transferred to one of the strontium atoms to turn it to the Rydberg atom with a very large atomic radius. In other words, we can say that this atom is in excited state where the electron is far away from the reach of nucleus and very small effect of nucleus is shown on the electron. The radius of this atom is much bigger than the radius for usual atom. At this point, the electron revolves in its own orbit and the other strontium atom lies inside this orbit (between the Rydberg nuclei and the last shell). 

Depending upon the radius of this newly created Rydberg atom, more than 170 other atoms can fit into it.

Stability?

Computer simulations show that a weak interaction decreases the total energy of the system and a bond is formed between the Rydberg atom and other atoms. The bonds between the Rydberg atom and other strontium atom is much weaker as compared to bonds in other crystal systems. If the particles were moving any faster, the bond has broken and we will not be able to detect this state.

First, a Bose-Einstein condensate was created with strontium atoms. Using a laser, energy was transferred to one of these atoms, turning it into a Rydberg atom with a huge atomic radius. The radius of the orbit in which the electron moves around the nucleus is much larger than the typical distance between two atoms in the condensate. Therefore, the electron orbits its own atomic nucleus, while numerous other atoms lie inside its orbit, too. Depending on the radius of the Rydberg atom and the density of the Bose-Einstein condensate, as many as 170 additional strontium atoms may be enclosed by the huge electronic orbit.

Read more at: https://phys.org/news/2018-02-creation-rydberg-polarons-bose-gas.html#jCp

First, a Bose-Einstein condensate was created with strontium atoms. Using a laser, energy was transferred to one of these atoms, turning it into a Rydberg atom with a huge atomic radius. The radius of the orbit in which the electron moves around the nucleus is much larger than the typical distance between two atoms in the condensate. Therefore, the electron orbits its own atomic nucleus, while numerous other atoms lie inside its orbit, too. Depending on the radius of the Rydberg atom and the density of the Bose-Einstein condensate, as many as 170 additional strontium atoms may be enclosed by the huge electronic orbit.

Read more at: https://phys.org/news/2018-02-creation-rydberg-polarons-bose-gas.html#jCp