Techniques such as optical pumping are used to create population inversions in which electrons are placed into these types of states, from which they undergo a lasing cascade.
The quantum Zeno effect occurs when a quantum system in this type of state is measured frequently, causing it to remain in that state. This type of state is the operating basis for the bubble chamber, since the superheated liquid hydrogen used in those devices represents one realization of this kind of state. Techniques such as optical pumping are used to create population inversions in which electrons are placed into these types of states, from which they undergo a lasing cascade. This term characterizes the output of an element such as a flip-flop before it has settled following a transition, and a mechanical example of this type of state is a ball sitting on top of a hill which will roll down the hill if disturbed. For ten points, identify this type of state in which a system is in equilibrium but may easily transition to a lower energy state under any perturbation.
The quantum Zeno effect occurs when a quantum system in this type of state is measured frequently, causing it to remain in that state.
meta-stable [accept word forms]