Jack Lidmar

Virus shapes and buckling transitions in spherical shells.

We show that the icosahedral packings of protein capsomeres proposed by Caspar and Klug for spherical viruses become unstable to faceting for sufficiently large virus size, in analogy with the buckling instability of disclinations in two-dimensional crystals. Our model, based on the nonlinear physics of thin elastic shells, produces excellent one-parameter fits in real space to the full three-dimensional shape of large spherical viruses. The faceted shape depends only on the dimensionless Foppl-von Kármán number gamma=YR(2)/kappa, where Y is the two-dimensional Youngs modulus of the protein shell, kappa is its bending rigidity, and R is the mean virus radius. The shape can be parametrized more quantitatively in terms of a spherical harmonic expansion. We also investigate elastic shell theory for extremely large gamma, 10(3)<gamma<10(8), and find results applicable to icosahedral shapes of large vesicles studied with freeze fracture and electron microscopy.

Critical properties of Bose-glass superconductors

We study vortex lines in high-temperature superconductors with columnar defects produced by heavy-ion irradiation. We reconsider scaling theory for the Bose-glass transition with tilted magnetic fields, and propose, e.g., a new scaling form for the shape of the Bose glass phase boundary, which is relevant for experiments. We also consider Monte Carlo simulations for a vortex model with a screened interaction. Critical exponents are determined from scaling analysis of Monte Carlo data for current-voltage characteristics and other quantities. The dynamic critical exponent is found to be z = 4.6 ± 0.3.

Monte Carlo simulation of a two-dimensional continuum Coulomb gas

We study the classical two-dimensional (2D) Coulomb-gas model for thermal vortex fluctuations in thin superconducting/superfluid films by Monte Carlo simulation of a grand-canonical vortex ensemble ...

Josephson junction transmission lines as tunable artificial crystals

We investigate one-dimensional Josephson junction arrays with generalized unit cells, beyond a single junction or SQUID, as a circuit approach to engineer band gaps. Within a specific frequency ran ...

Dynamical universality classes of the superconducting phase transition

We present a finite temperature Monte Carlo study of the

Accelerated weight histogram method for exploring free energy landscapes

\mathrm{XY}

Localizing quantum phase slips in one-dimensional Josephson junction chains

model in the vortex representation and study its dynamical critical behavior in two limits. The first neglects magnetic-field fluctuations, corresponding to the absence of screening, which should be a good approximation in high-

Vortex glass transition in a random pinning model.

{T}_{c}

Spatial and temporal distribution of phase slips in Josephson junction chains

superconductors

Phase sticking in one-dimensional Josephson junction chains

(\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\kappa}}\ensuremath{\infty})