Fig 4 - uploaded by Thomas Nattermann
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Gibbs free energy density g(a; µ, T ) for several values of µ, with a vdw = 10 −5. The data reflects a second order transition from the Meissner phase to the mixed phase.
Source publication
In anisotropic or layered superconductors thermal fluctuations as well as impurities induce a van der Waals (vdW) attraction between flux lines, as has recently been shown by Blatter and Geshkenbein in the thermal case [Phys. Rev. Lett. 77, 4958 (1996)] and by Mukherji and Nattermann in the disorder dominated case [Phys. Rev. Lett. 79, 139 (1997)]....
Context in source publication
Context 1
... Figs. 4 and 5, the Gibbs free energy density g(a; µ, T ) as defined in (27) is plotted for two different values of a vdw . For these two values of the vdW amplitude, the transition from the Meissner state to the mixed phase has different characteristics: For a vdw = 10 −5 , the transition is con- tinuous because the minimum position of the ...
Citations
The problem of a vortex electromagnetic mass in a superconductor is considered accounting for the self‐interaction effect conditioned by the coupling of the moving vortex to the excited fluctuations of the superfluid density. In the framework of the phenomenological model used, the self‐interaction is defined as an interaction of the singular phase with the induced polarization of the charged superfluid. The obtained polaron‐type mass exceeds the earlier obtained electromagnetic mass in view of the large value of the light speed relation to the Fermi velocity c/vF
, and can dominate over the vortex core mass.
The elastic moduli of vortex crystals in anisotropic superconductors are frequently involved in the investigation of their phase diagram and transport properties. We provide a detailed analysis of the harmonic eigenvalues (normal modes) of the vortex lattice for general values of the magnetic field strength, going beyond the elastic continuum regime. The detailed behavior of these wavevector-dependent eigenvalues within the Brillouin zone (BZ), is compared with several frequently used approximations that we also recalculate. Throughout the BZ, transverse modes are less costly than their longitudinal counterparts, and there is an angular dependence which becomes more marked close to the zone boundary. Based on these results, we propose an analytic correction to the nonlocal continuum formulas which fits quite well the numerical behavior of the eigenvalues in the London regime. We use this approximate expression to calculate thermal fluctuations and the full melting line (according to Lindeman's criterion) for various values of the anisotropy parameter.
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 vortex lines onto the imaginary time quantum mechanics of two dimensional charged bosons allows us to define a 2D Casimir problem: Two half-spaces of (dilute) 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 previously found by Blatter and Geshkenbein [Phys. Rev. Lett. 77, 4958 (1996)]
