The effects of counter-rotating terms(CRTs)on Rabi splitting and the dynamic evolution of atomic population in the Jaynes–Cummings model are studied with a coherent-state approach.When the coupling strength increases,the Rabi splitting becomes of multi-Rabi frequencies for the initial state of an excited atom in a vacuum field,and the collapses and revivals gradually disappear,and then reappear with quite good periodicity.Without the rotating-wave approximation(RWA),the initial excited state contains many eigenstates rather than two eigenstates under the RWA,which results in the multi-peak emission spectrum.An analytical approximate solution for the strong coupling regime is obtained,which gives a new oscillation frequency and explains the recovery of collapses and revivals due to the equal energy spacing.
The controllable optical mirror is experimentally accomplished in a A-type three-level atomic system coupled with standing wave. It is shown that the reflection of probe light results from electromagnetically-induced-transparency-based four-wave mixing, therefore the reflection efficiency is highly dependent on the angle for phase matching condition between the probe and coupling fields. The measured reflection spectra show good agreement with dispersion compensation theory.
In this paper, we study an optomechanical device consisting of a Fabry-P6rot cavity with two dielectric nanospheres trapped near the cavity mirrors by an external driving laser. In the condition where the distances between the nanospheres and cavity mirrors are small enough, the Casimir force helps the optomechanical coupling to induce a steady-state optomechanical entanglement of the mechanical and optical modes in a certain regime of parameters. We investigate in detail the dependence of the steady- state optomechanical entanglement on external control parameters of the system, i.e., the effective detuning, the pump powers of the cavity, the cavity decay rate and the wavelength of the driving field. It is found that the large steady-state optomechanical entanglement, i.e. EN = 5.76, can be generated with experimentally feasible parameters, i.e. the pump power P = 18.2 μW, the cavity decay rate K = 0.5 MHz and the wavelength of the laser AL=1064 nm, which should be checked by optical measurement.
The intrinsic dynamics of two interacting electric polarized nanorods is theoretically investigated. The relative motion between them caused by electric dipole-dipole interaction is derived based on the generalized Lagrangian formulation. The results show that the relative translation and rotation are nonlinear and closely dependent on the initial configuration of the two nanorods. Furthermore, the general conditions of the initial configuration, which determine the two nanorods to repel or attract each other at the initial time, are obtained. The two-dimensional relative motion of the two nanorods shows that the antiparallel and head-to-tail ordering stable self-assembly are respectively formed in two planar initial configurations. For different three-dimensional initial configurations, the interesting dynamic relative attraction, repulsion, and oscillation with rotation are respectively realized. Finally, the theoretical schemes which realize the relaxing, direct head-to-tail ordering, and direct antiparallel ordering stable self-assembly are presented according to the different modes of the motion of the nanoparticles. Some of our results agree well with the results of experiments and simulations.
