@article { ISI:000236467500180,
	title = {All-optical digital logic: Full addition or subtraction on a three-state system},
	journal = {PHYSICAL REVIEW A},
	volume = {73},
	year = {2006},
	month = {MAR},
	abstract = {Stimulated Raman adiabatic passage (STIRAP) is a well-studied pump-probe control scheme for manipulating the population of quantum states of atoms or molecules. By encoding the digits to be operated on as {\textquoteleft}{\textquoteleft}on{\textquoteright}{\textquoteright} or {\textquoteleft}{\textquoteleft}off{\textquoteright}{\textquoteright} laser input signals we show how STIRAP can be used to implement a finite-state logic machine. The physical conditions required for an effective STIRAP operation are related to the physical conditions expected for a logic machine. In particular, a condition is derived on the mean number of photons that represent an on pulse. A finite-state machine computes Boolean expressions that depend both on the input and on the present state of the machine. With two input signals we show how to implement a full adder where the carry-in digit is stored in the state of the machine. Furthermore, we show that it is possible to store the carry-out digit as the next state and thereby return the machine to a state ready for the next full addition. Such a machine operates as a cyclical full adder. We further show how this full adder can equally well be operated as a full subtractor. To the best of our knowledge this is the first example of a nanosized system that implements a full subtraction.},
	issn = {1050-2947},
	doi = {10.1103/PhysRevA.73.033820},
	author = {Remacle, F. and LEVINE, RD}
}
