Casimir Force between two Half Spaces of Vortex Matter in Anisotropic Superconductors

We present a new approach to calculate the attractive long-range vortex-vortex interaction of the van der Waals type present in anisotropic and layered superconductors. The mapping of the statistical mechanics of two-dimensional charged bosons allows us to define a Casimir problem: Two half spaces of vortex matter separated by a gap of width R are mapped to two dielectric half planes of charged bosons interacting via a massive gauge field. We determine the attractive Casimir force between the two half planes and show that it agrees with the pairwise summation of the van der Waals force between vortices.Comment: Submitted to Physica C (4 pages, 2 figures

Density functional theory of vortex lattice melting in layered superconductors: a mean-field--substrate approach

We study the melting of the pancake vortex lattice in a layered superconductor in the limit of vanishing Josephson coupling. Our approach combines the methodology of a recently proposed mean-field substrate model for such systems with the classical density functional theory of freezing. We derive a free-energy functional in terms of a scalar order-parameter profile and use it to derive a simple formula describing the temperature dependence of the melting field. Our theoretical predictions are in good agreement with simulation data. The theoretical framework proposed is thermodynamically consistent and thus capable of describing the negative magnetization jump obtained in experiments. Such consistency is demonstrated by showing the equivalence of our expression for the density discontinuity at the transition with the corresponding Clausius-Clapeyron relation.Comment: 11 pages, 4 figure

Dynamical resurrection of the visibility in a Mach-Zehnder interferometer

We study a single-electron pulse injected into the chiral edge-state of a quantum Hall device and subject to a capacitive Coulomb interaction. We find that the scattered multi-particle state remains unentangled and hence can be created itself by a suitable classical voltage-pulse $V(t)$. The application of the inverse pulse $-V(-t)$ corrects for the shake-up due to the interaction and resurrects the original injected wave packet. We suggest an experiment with an asymmetric Mach-Zehnder interferometer where the application of such pulses manifests itself in an improved visibility.Comment: 4 pages, 1 figur