Erratum: Effective Lorentz Force due to Small-Angle Impurity Scattering: Magnetotransport in High-TcT_c Superconductors

The equations in cond-mat/0011020 and Phys. Rev, Lett. 86, 4652 (2001) are valid but a numerical estimate in the paper is incorrect.Comment: An erratum for cond-mat/0011020 and Phys. Rev, Lett. 86, 4652 (2001

Applying black hole perturbation theory to numerically generated spacetimes

Nonspherical perturbation theory has been necessary to understand the meaning of radiation in spacetimes generated through fully nonlinear numerical relativity. Recently, perturbation techniques have been found to be successful for the time evolution of initial data found by nonlinear methods. Anticipating that such an approach will prove useful in a variety of problems, we give here both the practical steps, and a discussion of the underlying theory, for taking numerically generated data on an initial hypersurface as initial value data and extracting data that can be considered to be nonspherical perturbations.Comment: 14 pages, revtex3.0, 5 figure

Cauchy-perturbative matching and outer boundary conditions: computational studies

We present results from a new technique which allows extraction of gravitational radiation information from a generic three-dimensional numerical relativity code and provides stable outer boundary conditions. In our approach we match the solution of a Cauchy evolution of the nonlinear Einstein field equations to a set of one-dimensional linear equations obtained through perturbation techniques over a curved background. We discuss the validity of this approach in the case of linear and mildly nonlinear gravitational waves and show how a numerical module developed for this purpose is able to provide an accurate and numerically convergent description of the gravitational wave propagation and a stable numerical evolution.Comment: 20 pages, RevTe

Anisotropic in-plane resistivity in the nematic phase of the iron pnictides

We show that the interference between scattering by impurities and by critical spin fluctuations gives rise to anisotropic transport in the Ising-nematic state of the iron pnictides. The effect is closely related to the non-Fermi liquid behavior of the resistivity near an antiferromagnetic quantum critical point. Our theory not only explains the observed sign of the resistivity anisotropy $\Delta\rho$ in electron doped systems, but also predicts a sign change of $\Delta\rho$ upon sufficient hole doping. Furthermore, our model naturally addresses the changes in $\Delta\rho$ upon sample annealing and alkaline-earth substitution.Comment: revised version accepted in PRL; supplemental material include

There\u27s A Million Heroes in Each Corner of the U.S.A

[Verse 1] Virginia gave us Washington, way back in Sev’nty six Kentucky gave us Lincoln when our boys were in a fix Ohio gave us Grant and Dixie gave us Lee They fought it out and patched it up and made our history If you asked Uncle Sammy who could take their place today He’d rub his chin and with a grin he’d answer in this way. [Chorus] There’s a million heroes in each corner of the U.S.A. In cities and farms They’ve taken up arms The East and West have sent their best the rest are coming from the land of cotton You can bank on ev’ry loyal Yank to fight till the end of the fray When danger threatens they all rally ‘round That’s why the flag has never touched the ground There’s a million heroes in each corner of the U.S.A. [Verse 2] Columbus found America the home of peace and rest And Betsy Ross she found a flag to stand each battle test Tho’ heroes of the past have laid away the gun Their spirits live within the hearts of ev’ry native son Our flag is just as clean today as when it first was made each stripe and star a battle scar and still I’m not afraid. [Chorus

S-Duality at the Black Hole Threshold in Gravitational Collapse

We study gravitational collapse of the axion/dilaton field in classical low energy string theory, at the threshold for black hole formation. A new critical solution is derived that is spherically symmetric and continuously self-similar. The universal scaling and echoing behavior discovered by Choptuik in gravitational collapse appear in a somewhat different form. In particular, echoing takes the form of SL(2,R) rotations (cf. S-duality). The collapse leaves behind an outgoing pulse of axion/dilaton radiation, with nearly but not exactly flat spacetime within it.Comment: 8 pages of LaTeX, uses style "revtex"; 1 figure, available in archive, or at ftp://ftp.itp.ucsb.edu/figures/nsf-itp-95-15.ep

Plasmonic Scaling of Superconducting Metamaterials

Superconducting metamaterials are utilized to study the approach to the plasmonic limit simply by tuning temperature to modify the superfluid density, and thus the superfluid plasma frequency. We examine the persistence of artificial magnetism in a metamaterial made with superconductors in the plasmonic limit, and compare to the electromagnetic behavior of normal metals as a function of frequency as the plasma frequency is approached from below. Spiral-shaped Nb thin film meta-atoms of scaled dimensions are employed to explore the plasmonic behavior in these superconducting metamaterials, and the scaling condition allows extraction of the temperature dependent superfluid density, which is found to be in good agreement with expectations.Comment: 5 pages, 3 figure