That "quantum fingerprint" was then converted back into light by again shining a laser on them. Usually, any information about light is destroyed when its photons are absorbed by atoms. In these studies, the information was preserved.
"We're writing the information about the pulse into the atoms and at a later time we're reading the information out," Phillips said.
According to Phillips, the information about the light could in principle be stored for as long as a second. He said future research might focus on doing the reverse of the current study--reading the quantum states of atoms with light.
The ability to store and retrieve such quantum information would be an important step toward developing quantum computers, which unlike normal computers, could use bits that can exist simultaneously as zero and one and would be immensely more powerful than purely digital computers.
Hau could not be reached yesterday for comment.
--Staff writer Jonathan H. Esensten can be reached at esensten@fas.harvard.edu.