Fluctuation theorem and large deviation function for a solvable model of a molecular motor (2008)
Lacoste, D., Lau, A. W. C., Mallick, K.
We study a discrete stochastic model of a molecular motor. This discrete model can be viewed as a \emph{minimal} ratchet model. We extend our previous work on this model, by further investigating the...
Fluctuations and Rheology in Active Bacterial Suspensions (2007)
Chen, D. T. N., Lau, A. W. C., Hough, L. A., Islam, M. F., Goulian, M., Lubensky, T. C., ...
We probe non-equilibrium properties of an active bacterial bath through measurements of correlations of passive tracer particles and the response function of a driven, optically trapped tracer. These...
Non-equilibrium fluctuations and mechanochemical couplings of a molecular motor (2007)
Lau, A. W. C., Lacoste, D., Mallick, K.
We investigate theoretically the violations of Einstein and Onsager relations, and the efficiency for a single processive motor operating far from equilibrium using an extension of the two-state...
State-dependent diffusion: thermodynamic consistency and its path integral formulation (2007)
Lau, A. W. C., Lubensky, T. C.
The friction coefficient of a particle can depend on its position as it does when the particle is near a wall. We formulate the dynamics of particles with such state-dependent friction coefficients...
Dynamics of bacterial flow: Emergence of spatiotemporal coherent structures (2007)
Sambelashvili, Nicholas, Lau, A. W. C., Cai, David
We propose a simple model of self-propelled particles to show that coherent structures, such as jets and swirls, can arise from a plausible microscopic mechanisms: (i) the elongated shape of the...
Dynamics of active membranes with internal noise (2006)
We study the time-dependent height fluctuations of an active membrane containing energy-dissipating pumps that drive the membrane out of equilibrium. Unlike previous investigations based on models...
Charged Plate Beyond Mean-field: One-loop Corrections by Salt-density Fluctuation (2006)
We present an exact field-theoretic formulation for a fluctuating, generally asymmetric, salt density in the presence of a charged plate. The non-linear Poisson-Boltzmann equation is obtained as the...
Elongation and Fluctuations of Semi-flexible Polymers in a Nematic Solvent (2004)
Dogic, Z., Zhang, J., Lau, A. W.C., Aranda-Espinoza, Helim, Dalhaimer, Paul M, Discher, Dennis E, ...
We directly visualize single polymers with persistence lengths ranging from lp = 0:05 to 16 µm, dissolved in the nematic phase of rod-like fd virus. Polymers with sufficiently large persistence...
Elongation and fluctuations of semi-flexible polymers in a nematic solvent (2004)
Dogic, Z., Zhang, J., Lau, A. W. C., Aranda-Espinoza, H., Dalhaimer, P., Discher, D. E., ...
We directly visualize single polymers with persistence lengths ranging from $\ell_p=0.05$ to 16 $\mu$m, dissolved in the nematic phase of rod-like {\it fd} virus. Polymers with sufficiently large...
Microrheology, Stress Fluctuations, and Active Behavior of Living Cells (2003)
Lau, A. W. C., Hoffman, Brenton D, Davies, A., Crocker, John C, Lubensky, Thomas C.
We report the first measurements of the intrinsic strain fluctuations of living cells using a recently developed tracer correlation technique along with a theoretical framework for interpreting such...
Microrheology, stress fluctuations and active behavior of living cells (2003)
Lau, A. W. C., Hoffman, B. D., Davies, A., Crocker, J. C., Lubensky, T. C.
We report the first measurements of the intrinsic strain fluctuations of living cells using a recently-developed tracer correlation technique along with a theoretical framework for interpreting such...
Effects of counterion fluctuations in a polyelectrolyte brush (2003)
Santangelo, C. D., Lau, A. W. C.
We investigate the effect of counterion fluctuations in a single polyelectrolyte brush in the absence of added salt by systematically expanding the counterion free energy about Poisson-Boltzmann mean...
Counterion Condensation and Fluctuation-Induced Attraction (2002)
We consider an overall neutral system consisting of two similarly charged plates and their oppositely charged counterions and analyze the electrostatic interaction between the two surfaces beyond the...
Spreading of Latex Particles on a Substrate (2002)
Lau, A. W. C., Portigliatti, M., Raphael, E., Leger, L.
We have investigated both experimentally and theoretically the spreading behavior of latex particles deposited on solid substrates. These particles, which are composed of cross-linked polymer chains,...
Lau, A. W. C., Lin, Keng-Hui, Yodh, A. G.
We compute the entropic interactions between two colloidal spheres immersed in a dilute suspension of semi-flexible rods. Our model treats the semi-flexible rod as a bent rod at fixed angle, set by...
Charge Fluctuations and Counterion Condensation (2002)
Lau, A. W. C., Lukatsky, D. B., Pincus, P., Safran, S. A.
We predict a condensation phenomenon in an overall neutral system, consisting of a single charged plate and its oppositely charged counterions. Based on the ``two-fluid'' model, in which the...
Phase Transitions in Lyotropic Nematic Gels (2002)
Lacoste, D., Lau, A. W. C., Lubensky, T. C.
In this paper, we discuss the equilibrium phases and collapse transitions of a lyotropic nematic gel immersed in an isotropic solvent. A nematic gel consists of a cross-linked polymer network with...
Electrostatic Attraction of Coupled Wigner Crystals: Finite Temperature Effects (2000)
Lau, A. W. C., Pincus, P., Levine, Dov, Fertig, H. A.
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...
Novel Electrostatic Attraction from Plasmon Fluctuations (2000)
Lau, A. W. C., Levine, Dov, Pincus, P.
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...
Binding of Oppositely Charged Membranes and Membrane Reorganization (1998)
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...
Charge-Fluctuation-Induced Non-analytic Bending Rigidity (1998)
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...