Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2004-05-06
Physics
Condensed Matter
Statistical Mechanics
8 pages, in press in J. Phys. A, Letters to the Editor
Scientific paper
10.1088/0305-4470/37/24/L02
How do charge and density fluctuations compete in ionic fluids near gas-liquid criticality when quantum mechanical effects play a role ? To gain some insight, long-range $\Phi^{{\mathcal{L}}}_{\pm \pm} / r^{d+\sigma}$ interactions (with $\sigma>0$), that encompass van der Waals forces (when $\sigma = d = 3$), have been incorporated in exactly soluble, $d$-dimensional 1:1 ionic spherical models with charges $\pm q_0$ and hard-core repulsions. In accord with previous work, when $d>\min \{\sigma, 2\}$ (and $q_0$ is not too large), the Coulomb interactions do not alter the ($q_0 = 0$) critical universality class that is characterized by density correlations at criticality decaying as $1/r^{d-2+\eta}$ with $\eta = \max \{0, 2-\sigma\}$. But screening is now algebraic, the charge-charge correlations decaying, in general, only as $1/r^{d+\sigma+4}$; thus $\sigma = 3$ faithfully mimics known \textit{non}critical $d=3$ quantal effects. But in the \textit{absence} of full ($+, -$) ion symmetry, density and charge fluctuations mix via a transparent mechanism: then the screening \textit{at criticality} is \textit{weaker} by a factor $r^{4-2\eta}$. Furthermore, the otherwise valid Stillinger-Lovett sum rule fails \textit{at} criticality whenever $\eta =0$ (as, e.g., when $\sigma>2$) although it remains valid if $\eta >0$ (as for $\sigma<2$ or in real $d \leq 3$ Ising-type systems).
Aqua Jean-Noel
Fisher Michael E.
No associations
LandOfFree
Charge and Density Fluctuations Lock Horns : Ionic Criticality with Power-Law Forces 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 Charge and Density Fluctuations Lock Horns : Ionic Criticality with Power-Law Forces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Charge and Density Fluctuations Lock Horns : Ionic Criticality with Power-Law Forces will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-711841