Monthly Archives: June 2015

Experimental observation of crystalline particle flows in toroidal dust clouds

The dust flow in a toroidal dust trap is studied experimentally. The flow is driven by the Hall component of the ion drag force in a magnetized plasma. Dust density waves are found in a torus with a large minor radius a, which allows for several wavelength, 2 a > 5 λ , in the (mostly) radial direction of the ion flow. Beyond an intermediate state with radial sloshing oscillations, a crystalline dust flow with suppressed wave activity could be realized for 2 a 2 λ . The particles arrange themselves in distinct layers with hexagonal-like local order. Smooth transitions between states with different numbers of layers are found in the inhomogeneous flow.

Modified Enskog Kinetic Theory for Strongly Coupled Plasmas. (arXiv:1506.03112v1 [physics.plasm-ph])

Concepts underlying the Enskog kinetic theory of hard-spheres are applied to include short-range correlation effects in a model for transport coefficients of strongly coupled plasmas. The approach is based on an extension of the effective potential transport theory [S.~D.~Baalrud and J.~Daligault, Phys.~Rev.~Lett.~{\bf 110}, 235001 (2013)] to include an exclusion radius surrounding individual charged particles that is associated with Coulomb repulsion. This is obtained by analogy with the finite size of hard spheres in Enskog's theory. Predictions for the self-diffusion and shear viscosity coefficients of the one-component plasma are tested against molecular dynamics simulations. The theory is found to accurately capture the kinetic contributions to the transport coefficients, but not the potential contributions that arise at very strong coupling ($\Gamma \gtrsim 30$). Considerations related to a first-principles generalization of Enskog's kinetic equation to continuous potentials are also discussed.

Nonlinear Dust Acoustic Waves in Strongly Coupled Quantum Dusty Plasmas

Using a set of fluid equations to describe the inertial dust grain component in dense collisionless unmagnetized quantum dusty plasmas, where the electrons and ions obey the Thomas–Fermi density distribution, the propagation characteristics of dust acoustic solitary waves (DASWs) are studied. First, a linear dispersion of dust acoustic wave (DAW) is obtained, and it is shown that the DAW is modified by a strongly coupled parameter. Then for small amplitude solitary waves, the Korteweg-de Vries equation is obtained by applying the reductive perturbation technique. For arbitrary amplitude solitary waves, the Sagdeev potential method is employed and the Sagdeev potential is analyzed. In both cases, the effect of dust coupling parameters on the characteristics of DASWs in our system are analyzed.

Coherent Generation of Nonclassical Light on Chip via Detuned Photon Blockade

Author(s): Kai Müller, Armand Rundquist, Kevin A. Fischer, Tomas Sarmiento, Konstantinos G. Lagoudakis, Yousif A. Kelaita, Carlos Sánchez Muñoz, Elena del Valle, Fabrice P. Laussy, and Jelena Vučković

The on-chip generation of nonclassical states of light is a key requirement for future optical quantum hardware. In solid-state cavity quantum electrodynamics, such nonclassical light can be generated from self-assembled quantum dots strongly coupled to photonic crystal cavities. Their anharmonic st...

[Phys. Rev. Lett. 114, 233601] Published Mon Jun 08, 2015

Extended analysis of quasielastic scattering of 9 Li+ 12 C

Abstract We present a new analysis of the quasielastic scattering of a 9Li projectile by a target 12C nucleus at 540 MeV. First, we obtain the elastic scattering results by using the double folding model (DFM) with the M3Y effective nucleon-nucleon (Michigan 3 Yukawa) interaction. We find the inelastic scattering results for excited states of both the projectile’s nucleus and the target’s nucleus in the coupled-channels (CC) formalism. In this context, the deformed states of the Coulomb potential, nuclear potential and Coulomb+nuclear potentials are investigated separately. Moreover, these calculations are repeated for different deformation parameters (ß) of the 9Li projectile. The quasielastic scattering results of excited states of both nuclei are calculated. Finally, the effect of the surface potential on the DFM results is examined. The obtained results provide an opportunity for a test of different theoretical model calculations in explaining the quasielastic scattering of 9Li+12C.