arXiv subjects

A. W. C. Lau

Publications and source records attributed to A. W. C. Lau.

22 records · Page 2Linked to original sources

arXiv2000

Electrostatic Attraction of Coupled Wigner Crystals: Finite Temperature Effects

In this paper, we present a unified physical picture for the electrostatic attraction between two coupled planar Wigner crystals at finite (but below their melting) temperature. At very low temperatures, we find a new regime where the attraction, arising from the long-wavelength excitation of the plasmon mode, scales with the interplanar distance $d$ as $d^{-2}$. At higher temperatures, our calculation agrees with known results. Furthermore, we analyze the temperature dependence of the short-ranged attraction arising from ``structural'' correlations and argue that thermal fluctuations drastically reduce the strength of this attraction.

cond-mat.soft↗

arXiv2000

Novel Electrostatic Attraction from Plasmon Fluctuations

In this Letter, we show that at low temperatures, zero-point fluctuations of the plasmon modes of two mutually coupled 2-D planar Wigner crystals give rise to a novel long-range attractive force. For the case where the distance $d$ between two planar surfaces is large, this attractive force has an unusual power-law decay, which scales as $d^{-7/2},$ unlike other fluctuation-induced forces. Specifically, we note that its range is longer than the ``standard'' zero-temperature van der Waals interaction. This result may in principle be observed in bilayer electronic systems and provides insight into the nature of correlation effects for highly charged surfaces.

cond-mat.soft↗

arXiv1998

Binding of Oppositely Charged Membranes and Membrane Reorganization

We consider the electrostatic interaction between two rigid membranes, with different surface charge densities of opposite sign, across an aqueous solution without added salt. Exact solutions to the nonlinear Poisson-Boltzmann equation are obtained and their physical meaning discussed. We also calculate the electrostatic contribution to the free energy and discuss the renormalization of the area per head group of the charged lipids arising from the Coulomb interaction.

cond-mat.soft↗

arXiv1998

Charge-Fluctuation-Induced Non-analytic Bending Rigidity

In this Letter, we consider a neutral system of mobile positive and negative charges confined on the surface of curved films. This may be an appropriate model for: i) a highly charged membrane whose counterions are confined to a sheath near its surface; ii) a membrane composed of an equimolar mixture of anionic and cationic surfactants in aqueous solution. We find that the charge fluctuations contribute a non-analytic term to the bending rigidity that varies logarithmically with the radius of curvature. This may lead to spontaneous vesicle formation, which is indeed observed in similar systems.

cond-mat.soft↗