Related papers: Model of Flux Trapping in Cooling Down Process
Vortex dynamics in a bilayer thin film superconductor are studied through a Josephson-coupled double layer XY model. A renormalization group analysis shows that there are three possible states associated with the relative phase of the…
We explore the nature of a certain type of supercooled phase transition, where the supercooling is guaranteed to end due to the curvature of the finite-temperature effective potential at the origin experiencing a sign flip at some…
The tunneling rate t_v of a vortex between two pinning sites (of strength V separated by d) is computed using the Bogoliubov expansion of vortex wavefunctions overlap. For BCS vortices, tunneling is suppressed beyond a few Fermi…
Rings are a model system for studying phase coherence in one dimension. Superconducting rings have states with uniform phase windings that are integer multiples of 2$\pi$ called fluxoid states. When the energy difference between these…
A first order perturbation with respect to velocity has been employed to find the frictional damping force imposed on a single moving charge due to a perturbative electric field, inside a long circular cylindrical trap. We find that the…
We measured and compared the electric field vs current density characteristics in the vortex state of two amorphous Nb0.7Ge0.3 microbridges, with and without a line of submicron holes patterned along the sample axis. The power dissipation…
A Bose-Einstein condensate of cold atoms is a superfluid and thus responds to rotation of its container by the nucleation of quantized vortices. If the trapping potential is su ciently strong, there is no theoretical limit to the rotation…
The behavior of a dilute two-component superfluid Fermi gas subjected to rotation is investigated within the context of a weak-coupling BCS theory. The microscopic properties at finite temperature are obtained by iterating the Bogoliubov-de…
Superconducting transition, defined as vanishing of the resistivity, under a magnetic field in a clean bulk type II superconductor with weak sample disorder is believed to be a reflection of freezing of the vortex liquid to a kind of vortex…
The bound states that can occur in a superfluid vortex have recently called for attention owing to the capability of detecting them experimentally. However, a detailed theoretical account for the presence of these vortex bound states is…
Conventional superconductors are strong diamagnets that through the Meissner effect expel magnetic fields. It would therefore be surprising if a superconducting ground state would support spontaneous magnetics fields. Such time-reversal…
Recent experiments on the conductance of thin, narrow superconducting strips have found periodic fluctuations, as a function of the perpendicular magnetic field, with a period corresponding to approximately two flux quanta per strip area…
We report the experimental observation of the disruption of the superfluid atomic current flowing through an array of weakly linked Bose-Einstein condensates. The condensates are trapped in an optical lattice superimposed on a harmonic…
The work reported in my doctoral thesis is an experimental study of vortex dynamics and phase transitions in thin films of type II superconductors using scanning tunneling spectroscopy, low frequency ac susceptibility measurements and…
Type-II superconductors exhibit hysteretic behavior due to the presence of quantum vortices, and the order in which temperature and external field are varied plays a decisive role. Here we take current, rather than magnetic field, as the…
In underdoped cuprates fluctuations of the phase of the superconducting order parameter play a role due to the small superfluid density. We consider the effects of phase fluctuations assuming the exchange of spin fluctuations to be the…
The interplay between disorder and vortex--vortex interactions in strongly disordered superconductors in a magnetic field can stabilize a vortex-glass state, characterized by strong pinning and the absence of positional order. Yet its role…
The c-field simulation technique is used to study a trapped quasi-two dimensional Bose gas. We calculate the central curvature of the system density and fluctuations of the condensate mode in the degenerate regime. These results provide new…
Intrinsic c-axis tunnelling in the superconducting state has been measured in zero and finite fields in small mesa structures fabricated on the surface of 2212-BSCCO single crystals. The temperature dependence of the zero-field critical…
We discuss the low-temperature dynamics of magnetic flux lines in high-temperature superconductors in the presence of a family of parallel twin planes that contain the $c$ axis. A current applied along the twin planes drives flux motion in…