Scientists Create A Mega-Giant Atom Stuffed With Other Atoms

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

Scientists have contrived a new, exotic state of matter in a lab in Houston – a giant atom filled with other atoms.

The team, from the Vienna University of Technology and Harvard University, were pondering the very disturbing fact of life that pretty much everything is made up of a lot of empty space.

Within atoms, electrons usually orbit relatively far from their nucleus, leaving a big empty space that is basically nothingness at the heart of these tiny building blocks of the Universe. In this case, the scientists wondered if they couldn’t fill that space with something else, like a whole bunch of other atoms.

In atomic physics, scientists can create an atom, known as a Rydberg atom, in which one single electron is highly excited and orbits its nucleus at a very large distance.

“The average distance between the electron and its nucleus can be as large as several hundred nanometres - that is more than a thousand times the radius of a hydrogen atom,” said Professor Joachim Burgdörfer of Vienna University in a statement.

Burgdörfer and his colleague Professor Shuhei Yoshida decided to combine the theory of Rydberg atoms with Bose-Einstein condensates. This is a state of matter at which quantum physics can be more readily studied. Basically, scientists cool a dilute gas of bosons to temperatures close to absolute zero and in that condition, most of the bosons are in their lowest quantum state.

In collaboration with Rice University in Texas, the scientists developed a project to create a Bose-Einstein condensate with strontium atoms and then use a laser to transfer energy to one of the atoms and turn it into a Rydberg atom.

Computer simulations showed that the radius of the orbit of the electron of the Rydberg atom would be much larger than the typical distance between two atoms in the condensate. So what they ended up with was an electron that orbited around not just its own atomic nucleus, but as many as 170 additional strontium atoms that got stuck between them.