Atom lifetime extended using mirror
Researchers have succeeded in extending the lifetime of an artificial atom by ten times by positioning it in front of a mirror.
Scientists partly backed by the European Research Council at Chalmers University of Technology in Sweden placed an artificial atom at a specific distance in front of a short circuit that acts as a mirror. By changing the distance to the mirror, they can get the atom to live up to ten times as long as if the mirror had not been there.
The artificial atom is actually a superconducting electrical circuit that the researchers make behave as an atom. Just like a natural atom, it is possible to charge it with energy and excite the atom, which it then emits in the form of light particles. In this case, the light has a much lower frequency then ordinary light and in reality is microwaves. It normally takes some time before the atom loses energy and returns to its original state; this period is called the lifetime of the atom.
Per Delsing, physics professor and leader of the research team, said: “We have demonstrated how we can control the lifetime of an atom in a very simple way. We can vary the lifetime of the atom by changing the distance between the atom and the mirror.
“If we place the atom at a certain distance from the mirror the atom’s lifetime is extended by such a length that we are not even able to observe the atom. Consequently, we can hide the atom in front of a mirror.”
Göran Johansson, professor of theoretical and applied quantum physics and leader of the theory group, added: “The reason why the atom ‘dies’ … is that it sees the very small variations in the electromagnetic field which must exist due to quantum theory, known as vacuum fluctuations.”
When the atom is placed in front of the mirror it interacts with its mirror image, which changes the amount of vacuum fluctuations to which the atom is exposed.
The findings are published in the journal Nature Physics.
