Systematic study of projectile-structure effect on the fusion-barrier distribution

Abstract

Quasielastic excitation function measurement has been carried out for the 4 He + 232 Th system at θ lab = 160 • with respect to the beam direction, to obtain a representation of the fusion-barrier distribution. Using the present data along with previously measured barrier distribution results on 12 C, 16 O, and 19 F + 232 Th systems, a systematic analysis has been carried out to investigate the role of target and/or projectile structures on fusion-barrier distribution. It is observed that for 4 He, 12 C, and 16 O + 232 Th reactions, the couplings due to target states only are required in coupled-channel fusion calculations to explain the experimental data, whereas for the 19 F + 232 Th system along with the coupling of target states, inelastic states of 19 F are also required to explain the experimental results on fusion-barrier distribution. The width of the barrier distribution shows interesting transition behavior when plotted with respect to the target-projectile charge product for the above systems.

Pure dephasing vs. Phonon mediated off-resonant coupling in a quantum-dot-cavity system

“…The results reveals that the parameters P x , Γ x and Γ c remain constant, moreover it corroborates that the spontaneous emission can be neglected as it is usually done in many theoretical studies in the framework of the cQED. The most remarkable result to emerge from these data is that the phononic rates depend on the detuning accordingly to a Gaussian shape and it is consistent with other theoretical models that consider these particular phononic mechanisms at low temperatures (∼ 4K) [21,29,30]. To further prove that our mode can fit the experimental observation of Ref.…”

Explanation of the quantum phenomenon of off-resonant cavity-mode emission

“…Finally, the last term in the master equation describes the off-resonant QD-cavity coupling proposed by Majumdar et al [19] few years ago, as a physical mechanism able to compensate the QD-cavity frequency difference by the creation (or annihilation) of phonons at decay rate γ θ . Particularly, this phonon-mediated coupling mechanism has recently inspired investigations on electron-acousticphonon scattering in QD-cavity systems [20], as well as effects due to the phonon scattering on exciton-cavity interaction in the weak-coupling regime [21]. We compute numerically the emission spectra of the coupled system, according to the Wiener-Kinchine theorem, through the Fourier transformation of the cavity field autocorrelation…”

Filtering multiphoton emission from state-of-the-art cavity quantum electrodynamics

“…One of the main problems in semiconductor cavity QED implementations is the decoherence produced by the phonons induced by the lattice vibrations in the solid. It is a well known fact that phonons in cavity QED systems [69] give rise to two effects. The first one is the so-called pure dephasing mechanism, in which the phonons spoil the coherence of the 2LS without affecting directly the population.…”