Stimulated Raman adiabatic passage


Stimulated Raman adiabatic passage is a process that permits transfer of a population between two applicable quantum states via at least two coherent electromagnetic pulses. These light pulses drive the transitions of the three level Ʌ atom or multilevel system. The process is a form of state-to-state coherent control.

Population transfer in three level Ʌ atom

Consider the description of three level Ʌ atom having ground states and and excited state. Suppose in the beginning the total population is in the ground state. Here the logic for transformation of the population from ground state to is that initially the unpopulated states and couple, afterward superposition of states and couple to the state. Thereby a state is formed that permits the transformation of the population into state without populating the excited state. This process of transforming the population without populating the excited state is called the stimulated Raman adiabatic passage.