In multilevel system

Fundamentally, the conditions for lasing are detemiined unambiguously once the populations and coherences of the system density matrix are known. Yet, we have been unable to find in the literature any simple criterion for lasing in multilevel systems in temis of the system density matrix alone. Our conjecture is that entropy, as... 

Tannor D J and Rice S A 1987 Photon echoes in multilevel systems Understanding Molecular Properties ed J Avery et al (Dordrecht Reidel) p 205... 

J. Martin, B. W. Shore, and K. Bergmann. Coherent population transfer in multilevel systems with magnetic sublevels. 111. Experimental results. Phys. Rev. A, 54(2) 1556-1569(1996). 

Thus adiabatic passage in multilevel systems can be considered in general as global adiabatic passage combined with local diabatic evolutions near conical intersections. In multilevel systems, near a conical intersection, where one... 

In conclusion, we have presented a reliable method for selective production and detection of high-order atomic polarization moments based on the nonlinear magneto-optical effects with frequency modulated light. This method can be used for the selective control of higher order atomic coherences in multilevel systems exploiting large Kerr nonlinearities for the construction of all-optical quantum phase gates. 

Abstract Decay acceleration by frequent measurements (interruptions of the coupling), known as the anti-Zeno effect is argued to be much more ubiquitous than its inhibition in one- or two-level systems coupled to reservoirs (continua). In multilevel systems, frequent measurements cause accelerated decay by destroying the multilevel interference, which tends to inhibit decay in the absence of measurements. 

Transitions with parallel or antiparallel dipole moments can be created not only in multilevel systems but also in a two-level system driven by a polychromatic field [63]. In order to show this, we consider a two-level atom driven by a bichromatic field composed of a strong resonant laser field and a weaker laser field detuned from the atomic resonance by the Rabi frequency of the strong field. The effect of the strong field alone is to produce dressed states [35]... 

We now examine, as the next step in understanding how to control the time evolution of an excitation in an isolated molecule, the photon echo phenomenon in multilevel systems. The key question to be addressed is how the complications introduced by the multilevel character of a system are manifest in the coherent dynamics that determine the photon echo. 

J. Oreg, F.T. Hioe, J.H. Eberly, Adiabatic following in multilevel systems, Phys. Rev. A 29... 

H.J. Bauer, Son et lumiere or the optoacoustic effect in multilevel systems. J. Chem. Phys. 57,3130 (1972) (references to the historiceil development)... 

P. Marie, P. Zoller, J. L. Hall. Coherent atomic mirrors and beam splitters by adiabatic passage in multilevel systems. Physical Revew A. 1991 Oct 1 44(7) R4118-R4121. 

SO multilevel resists have not yet seen widespread manufacturing use. The limited selection of polymeric materials suitable for 157-nm resist formulation has brought renewed interest in multilevel systems. 

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