Jh. Eberly, THE DOUBLE-LAMBDA SYSTEM - A NEW WORKHORSE FOR QUANTUM OPTICS, Philosophical transactions-Royal Society of London. Physical sciences and engineering, 355(1733), 1997, pp. 2387-2391
We review the status of the double-lambda system of cavity QED and men
tion unexpected recent applications in which deterministic and unitary
control of quantum states is exploited.