Effective Hamiltonians for Detuned Systems - Daniel James

Highly detuned interactions appear in many instances in quantum optics, such as Raman transitions. Here I discuss a formalism to describe such interactions in systematic way, which results in a remarkably compact expression for an effective Hamiltonian, and I will also present recent results regarding the accuracy of the approximations used. To illustrate the technique I'll apply it to various situations which are well-known in experimental quantum optics (e.g., you can derive the A.C. Stark shift in three lines, without all that tedious mucking around with adiabatic elimination).