相关论文: Superconducting Coherence and the Helicity Modulus…
A model unifying superconductivity and antiferromagnetism using an underlying approximate SO(5) symmetry has injected energy into the field of high-temperature superconductivity. This model might lead to a variety of interesting solitons.…
Superfluid condensates are known to occur in contexts ranging from laboratory liquid helium to neutron stars, and are also likely to occur in cosmological phenomena such as axion fields. In the zero temperature limit, such condensates are…
Monte Carlo simulations are performed to study the properties of type-II superconducting films in a magnetic field in which the vortices move in the two-dimensional geometry represented by the surface of a sphere. No numerical evidence is…
The concept of the transition of type II superconductor into the Abrikosov state as the appearance of long-range phase coherence is considered. It is shown that this transition should be first order in ideal (without disorder)…
We present a variational study of the helicity moduli of an anisotropic quantum three-dimensional (3D) XY-model of YBCO in superconducting state. It is found that both the ab-plane and the c-axis helicity moduli, which are proportional to…
Superconductors have two key characteristics. They expel magnetic field and they conduct electrical current with zero resistance. However, both properties are compromised in high magnetic fields which can penetrate the material and create a…
Monte Carlo simulations of the frustrated 2D XY model were carried out at small commensurate values of the frustration $f$. For $f=1/30$ a single transition was observed at which phase coherence (finite helicity modulus) and vortex lattice…
We study the effect of a transport current on the vortex-line lattice in isotropic type-II superconductors in the presence of strong thermal fluctuations by means of 'driven-diffusion' Monte Carlo simulations of a discretized London theory…
In superconductors where the coherence length is comparable to the Fermi wavelength, the vortex viscosity depends on the velocity of the vortex, leading to non linear equations of motion. The trajectories of vortices driven by a. c. fields…
The phase transition in a model for vortex lines in high temperature superconductors with columnar defects, i.e., linearly correlated quenched random disorder, is studied with finite size scaling and Monte Carlo simulations. Previous…
We study the energetics of superconducting vortices in the SO(5) model for high-$T_c$ materials proposed by Zhang. We show that for a wide range of parameters normally corresponding to type II superconductivity, the free energy per unit…
We performed the first scanning tunneling spectroscopy measurements on the pyrochlore superconductor KOs2O6 (Tc = 9.6 K) in both zero magnetic field and the vortex state at several temperatures above 1.95 K. This material presents…
We investigate vortex lattice solutions in a holographic superconductor model in asymptotically $AdS_4$ spacetime which includes the gravitational backreaction of the vortex. The circular cell approximation, which is known to give a good…
We numerically compute the helicity modulus of the three-dimensional gauge glass by Monte Carlo simulations. Because the average free energy is independent of a twist angle, it is expected that the average helicity modulus, directly related…
The boson Hubbard model has been extensively studied as a model of the zero temperature superfluid/insulator transition in Helium-4 on periodic substrates. It can also serve as a model for vortex lines in superconductors with a magnetic…
The range of critical thermal fluctuations in classical bulk superconductors is extremely small and especially in low fields hardly experimentally inaccessible. With a new type of calorimeter we have been able to resolve a small lambda…
Vortices in a type-II superconductor form a lattice structure that melts when the thermal displacement of the vortices is an appreciable fraction of the distance between vortices. In an anisotropic high-Tc superconductor, such as YBa2Cu3Oy,…
We examine the question of thermal melting of the triangular Abrikosov vortex solid in two-dimensional superconductors or neutral superfluids. We introduce a model, which combines lowest Landau level (LLL) projection with the magnetic…
The anisotropic frustrated 3D XY model with strong disorder in the coupling constants is studied as a model of a disordered superconductor in an applied magnetic field. Simulations with the exchange Monte Carlo method are performed for…
We present a detailed study of a single vortex in a holographic symmetry breaking phase. At low energies the system flows to an nontrivial conformal fixed point. Novel vortex physics arises from the interaction of these gapless degrees of…