If you wait long enough, interactions with the environment will make the state behave like a conventional classical system. In many cases, this time is significantly short. DARPA, with an eye on practical quantum devices and sensors in compact sizes, has set its sight on demonstrating protocols that can dramatically extend the longevity of the coherence of quantum systems.
DARPA's Defense Sciences Office (DSO) today announced a new fundamental research program, Driven and Nonequilibrium Quantum Systems (DRINQS) to investigate a recent paradigm shift in quantum research, which maintains that periodically driving a system out of equilibrium may stabilize its coherence.
"A simple illustration of the concept of driving something out of equilibrium to increase its stability is the well-known trick of making an inverted broom stand up on the palm of your hand or on one of your fingertips," said Ale Lukaszew, DARPA program manager. "If you hold your hand still, the broom is unstable and will fall over quickly. But if you drive the broom out of equilibrium by moving your hand around periodically, you can make the broom very stable, so it remains upright indefinitely."