If a fluctuating medium is confined, the ensuing perturbation of its fluctuation spectrum generates Casimir-like effective forces acting on its confining surfaces. Near a continuous phase transition of such a medium the corresponding order parameter fluctuations occur on all length scales and therefore close to the critical point this effect acquires a universal character, i.e., to a large exte...

We present a study, employing high level ab initio methods, of electron localization-delocalization transitions along the dissociation path of the C4- anion to C2 and C2-. We find that at the equilibrium geometry, the symmetrical and nonsymmetrical configurations of the linear C4- anion are almost isoenergetic. However, along a collinear dissociation path, the dipole moment drops abruptly to ze...

%e have classified continuous phase transitions in physical systems where the order parameter transforms as a four-dimensional representation of a three-dimensional space group. For most active four-dimensional space-group representations the "phase diagrams" are obtained. %'e also give prescriptions to lift the degeneracy, occurring at the fourth-degree polynomical expansion of the free energy...

We show that if the excitations which become gapless at a quantum critical point also carry the electrical current, then a resistivity linear in temperature, as is observed in the copper-oxide high-temperature superconductors, obtains only if the dynamical exponent z satisfies the unphysical constraint, z < 0. At fault here is the universal scaling hypothesis that, at a continuous phase transit...

We propose a general strategy to determine universal properties induced by a nearby phase transition on a non-order parameter field. We use a general renormalizable Lagrangian, which contains the order parameter and a non-order parameter field, and respects all the symmetries present. We investigate the case in which the order parameter field depends only on space coordinates, and the case in w...

For models which exhibit a continuous phase transition in the thermodynamic limit a numerical study of small systems reveals a non-monotonic behaviour of the microcanonical specific heat as a function of the system size. This is in contrast to a treatment in the canonical ensemble where the maximum of the specific heat increases monotonically with the size of the system. A phenomenological theo...

For materials that harbour a continuous phase transition, the susceptibility of the material to various fields can be used to understand the nature of the fluctuating order and hence the nature of the ordered state. Here we use anisotropic biaxial strain to probe the nematic susceptibility of URu2Si2, a heavy fermion material for which the nature of the low temperature 'hidden order' state has ...

Low surface energy coatings or anti-wetting agents play an essential role in microelectronics, anti-fogging and anti-fouling applications, and even have promising medical applications. Currently, perfluoroalkyl substituted polymethacrylates (PFPMs) are widely in use, and the anti-wetting properties of these and related polymers are believed to arise from the segregation of CF groups to the surf...

effects of binary mixtures of ionic/nonionic (sodium dodecyl sulfate/2-heptanol or 1-decanol) and nonionic/nonionic surfactants (2-heptnol/1-decanol) on drop/interface coalescence of water drops in a continuous n-heptane phase were examined. the drop size reduced appreciably and the multi-step coalescence was suppressed finally as the concentration of each of the constituting components of surf...