Physics – Quantum Physics
Scientific paper
2008-07-03
J.Math.Phys.50:013511,2009
Physics
Quantum Physics
Scientific paper
10.1063/1.3040187
We consider spin-boson models composed by a single bosonic mode and an ensemble of $N$ identical two-level atoms. The situation where the coupling between the bosonic mode and the atoms generates real and virtual processes is studied, where the whole system is in thermal equilibrium with a reservoir at temperature $\beta^{-1}$. Phase transitions from ordinary fluorescence to superradiant phase in three different models is investigated. First a model where the coupling between the bosonic mode and the $j-th$ atom is via the pseudo-spin operator $\sigma^{,z}_{(j)}$ is studied. Second, we investigate the generalized Dicke model, introducing different coupling constants between the single mode bosonic field and the environment, $g_{1}$ and $g_{2}$ for rotating and counter-rotating terms, respectively. Finally it is considered a modified version of the generalized Dicke model with intensity-dependent coupling in the rotating terms. In the first model the zero mode contributes to render the canonical entropy a negative quantity for low temperatures. The last two models presents phase transitions, even when only Hamiltonian terms which generates virtual processes are considered.
Alcalde Aparicio M.
Kullock R.
Svaiter Nami F.
No associations
LandOfFree
Virtual Processes and Superradiance in Spin-Boson Models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Virtual Processes and Superradiance in Spin-Boson Models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Virtual Processes and Superradiance in Spin-Boson Models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-597094