Physics

  2010 MAR 9 - (VerticalNews.com) -- According to recent research from Abbottabad, Pakistan, "Recently it has been discovered that certain two-qutrit entangled states interacting with global and/or multi-local decoherence undergo distillability sudden death (DSD). We investigate this phenomenon for qutrit-qutrit systems interacting with statistically independent zero-temperature reservoirs."

  "We show that certain initially prepared free-entangled states become bound-entangled in a finite time due to the action of a Markovian dissipative environment. As there is no definitive criterion for separability/entanglement of density matrices with dimension greater than 6, therefore we believe that the results obtained in this paper are restricted to a specific family of states considered here," wrote M. Ali and colleagues ...read more

  2010 MAR 9 - (VerticalNews.com) -- "We present a general analysis of the influence of nonlinear optical absorption on terahertz generation via optical-difference frequency generation when reaching for the quantum conversion efficiency limit," scientists in Palermo, Italy report.

  "By casting the equations governing the process in a suitably normalized form, including either two-photon- or three-photon absorption terms, we have been able to plot universal charts for phase-matched optical-to-terahertz conversion for different values of the nonlinear absorption coefficients," wrote M. Cherchi and colleagues, University of Palermo ...read more

  2010 MAR 9 - (VerticalNews.com) -- "An effective range theory is used to study the elastic scattering of electrons by the ground state of hydrogen atoms in weakly coupled plasma environments for low electron energies. The plasma screening effect is represented by screened Coulomb potentials (SCPs) of Debye type," researchers in Taipei, Taiwan report.

  "Highly correlated and variationally determined wavefunctions for H- in plasmas are used to determine the effective range of the ion states. The results for S-wave singlet phase shifts for the incident electron momentum in the range [0, 0.75] au are reported, to the best of our knowledge, for the first time in the literature," wrote A. Ghoshal and colleagues, National Academy of Sciences ...read more