A semiclassical, four-level model of a nanosecond, chirped pulse interacting with all optically accessible hyperfine states in an ultracold alkali atom, e.g., the Rb, is analyzed aiming at population inversion within 5S1/2 electronic state. The nature of two-photon adiabatic passage performed by a single pulse having the bandwidth prior to chirping significantly narrower than the hyperfine spli...

The chemical bond arises from a redistribution of electronic charge when atoms are brought in close proximity. The bond in a solid results from the superposition of charge densities of all atoms in the system. In an atom all electrons reside in their ground states at equilibrium. Only a few low lying excited states are typically accessed. The chemical bond in the solid consists of excited elect...

Several molecules absorb light energy which they emit after a time difference (lifetime) as radiation energy. Molecules remain at a low energy level or the ground electronic singlet state (So) or the lowest vibrational level at room temperature (Noomnarm and Clegg, 2009). On absorption of a photon, the molecule is excited from So to the first electronic excited singlet state S1 within < 10-15 s...

Recent evidence which establishes that electronic energy transfer is the most common mechanism for quenching of organic triplet states by coordination compounds is discussed. It is pointed out that only when energy transfer produces ligand field excited states is there likely to be markedly different behaviour observed from that expected for a typical organic triplet energy acceptor. Transfer t...

We consider the thermodynamical limit of a gl(N) spin chain with arbitrary representation at each site of the chain. We consider excitations (with holes and new strings) above the vacuum and compute their corrections in 1 L to the densities and the energy.

In the last several years, the Casimir energy for a variety of 1+1-dimensional integrable models has been determined from the exact S-matrix. It is shown here how to modify the boundary conditions to project out the lowest-energy state, which enables one to find excited-state energies. This is done by calculating thermodynamic expectation values of operators which generate discrete symmetries. ...

The frequency behavior of the tunnel injection quantum dot vertical cavitysurface emitting laser (TIQD-VCSEL) is investigated by using an analyticalnumericalmethod on the modulation transfer function. The function is based on therate equations and is decomposed into components related to different energy levelsinside the quantum dot and injection well. In this way, the effect of the tunnelingpr...