Related papers: Large-N $\beta$-function for superconducting films…
We study the beta functions for four-dimensional conformal gravity using two different parametrizations of metric fluctuation, linear split and exponential parametrization. We find that after imposing the traceless conditions, the beta…
The distinction between type I and type II superconductivity is re-examined in the context of the SO(5) model recently put forth by Zhang. Whereas in conventional superconductivity only one parameter (the Ginzburg-Landau parameter $\kappa$)…
We propose a mechanism responsible for the abrupt vanishing of the dendritic flux instability found in many superconducting films when an increasing magnetic field is applied. The onset of flux avalanches and the subsequent reentrance of…
Polycrystalline thin films of $\mathrm{Nb}_{1-x}\mathrm{U}_{x}$ solid solutions with $0.15\leq x \leq 0.40$ were prepared via d.c. magnetron sputtering at ambient conditions. X-ray characterisation of the samples revealed a systematic shift…
The nature of the superconducting transition in highly underdoped thick films of La$_{2-x}$Sr$_x$CuO$_4$ ($x=0.07$ and 0.08) has been investigated using the in-plane transport measurements. The contribution of superconducting fluctuations…
We consider the time-dependent Ginzburg-Landau model of superconductivity in the presence of an electric current flowing through a two-dimensional wire. We show that when the current is sufficiently strong the solution converges in the…
We study a generalized Ginzburg-Landau equation that models a sample formed of a superconducting/normal junction and which is not submitted to an applied magnetic field. We prove the existence of a unique positive (and bounded) solution of…
We show that inhomogeneities in the spatial distribution of Cooper pairs and in the phase of the local superconducting order parameter in the vicinity of a superconductor-normal state transition (SNT) in two dimensions can be highly…
The energy of a type II superconductor placed in a strong non-uniform, smooth and signed magnetic field is displayed via a universal characteristic function defined by means of a simplified two dimensional Ginzburg-Landau functional. We…
We have recently proposed a theoretical model for superconductors endowed with two distinct superconducting phases, described by two scalar order parameters which condensate at different critical temperatures. On analyzing the magnetic…
We report the temperature dependent magnetic penetration depth $\lambda(T)$ and the superconducting critical field $H_{c2}(T)$ in a 500-nm MgB$_{2}$ film. Our analysis of the experimental results takes into account the two gap nature of the…
We study the 2D full Ginzburg-Landau energy with a periodic rapidly oscillating, discontinuous and [strongly] diluted pinning term using a perturbative argument. This energy models the state of an heterogeneous type II supercon-ductor…
A nematic superconductor can in principle support a vestigial order phase above its superconducting transition temperature, with rotational symmetry spontaneously broken while remain nonsuperconducting. We examine the condition for this…
Thin superconducting films are usually regarded as type II superconductors even when they are made of a type I material. The reason is a strong contribution of the stray magnetic field that stabilizes vortices. While very thin films indeed…
We have measured the frequency and temperature dependences of complex ac conductivity, \sigma(\omega)=\sigma_1(\omega)-i\sigma_2(\omega), of NbN films in zero magnetic field between 0.1 to 10 GHz using a microwave broadband technique. In…
Superconductivity has been found in RuN films obtained by reactive magnetron sputtering. This is a novel member of the metal nitride superconductors family. The critical temperature of the superconducting transition varies depending on the…
The problem of the giant vortex state around a magnetic dot which is embedded in a superconducting film is investigated. The full non-linear, self-consistent Ginzburg-Landau equations are solved numerically in order to calculate the free…
We investigate the dependence of the order parameter profile, local and total susceptibilities on both the temperature and external magnetic field within the mean-filed Ginzburg-Landau Ising type model. We study the case of a film geometry…
We use the method of $\Gamma$-convergence to study the behavior of the Landau-de Gennes model for a nematic liquid crystalline film in the limit of vanishing thickness. In this asymptotic regime, surface energy plays a greater role and we…
We study a superconductor that is coupled to a superfluid via density and derivative couplings. Starting from a Lagrangian for two complex scalar fields, we derive a temperature-dependent Ginzburg-Landau potential, which is then used to…