Casimir–Polder forces from density matrix formalism

/ 06 04 03 3 v 1 5 A pr 2 00 6 Casimir - Polder forces from density matrix formalism

We use the density matrix formalism in order to calculate the energy level shifts, in second order on interaction, of an atom in the presence of a perfectly conducting wall in the dipole approximation. The thermal corrections are also examined when ¯ hω0/kBT = k0λT ≫ 1, where ω0 = k0c is the dominant transition frequency of the atom and λT is the thermal length. When the distance z between the ...

Open Quantum Systems: Density Matrix Formalism and Applications

Helicity Density Matrix Formalism and Polarized Processes in QCD

In this thesis, we shall first present helicity density matrix formalism to deal with the polarized processes in quantum chromodynamics(QCD), in which the calculations of the desired cross sections (or asymmetries in many cases) are simplified to take traces of products of helicity density matrices in the underlying particles' (partons, hadrons, etc.) helicity spaces. The parton distribution an...

Calculating populations of subcellular compartments using density matrix formalism

In our earlier paper (Ref. [1]) we developed an integrated probabilistic system for predicting the subcellular localization of proteins and estimating the relative populations of the various compartments in yeast. To justify our formulas we show here that there is a one-to-one correspondence between our previous calculations and the prediction of a state of a many-particle quantum system. The e...

Atom - wall dispersive forces from master equation formalism

Using the general expressions for level shifts obtained from the master equation for a small system interacting with a large one considered as a reservoir, we calculate the dispersive potentials between an atom and a wall in the dipole approximation. We analyze in detail the particular case of a two-level atom in the presence of a perfectly conducting wall. We study the van der Waals as well as...