from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To make (different parts of a circuit etc.) out of phase
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To put out of phase, as two parts of a single alternating current.
Reading the echo would allow researchers to figure out exactly how long the wavefunctions of the atoms would take to "dephase," or get all confused by environmental effects.
Simply looking at a qubit or in any other way letting it interact with the environment will cause it to decohere or dephase.