Related papers: Supercurrent flow through an effective double barr…
The problem of a quasi 1D {\it repulsive} BEC flow past through a nonlinear barrier is investigated. Two types of nonlinear barriers are considered, wide and short range ones. Steady state solutions for the BEC moving through a wide…
We theoretically investigate the critical velocity for dissipationless motion of a two-dimensional superfluid past a static potential barrier of large width. The circular-shaped barrier provides a comprehensive analytical framework for the…
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 investigate the flow of a one-dimensional nonlinear Schrodinger model with periodic boundary conditions past an obstacle, motivated by recent experiments with Bose--Einstein condensates in ring traps. Above certain rotation velocities,…
Supersonic flow of a superfluid past a slender impenetrable macroscopic obstacle is studied in the framework of the two-dimensional defocusing nonlinear Schr\"odinger (NLS) equation. This problem is of fundamental importance as a dispersive…
Earlier, in the CINT program at Los Alamos National Laboratory, we focused ultrafast mode-locked lasers on the tip-sample junction of a scanning tunneling microscope to generate currents at hundreds of harmonics of the laser pulse…
We have constructed conserved $\mathcal{N}=2$ higher-spin supercurrents for an arbitrary integer spin through the unconstrained superfield formulation of $4D,\, \mathcal{N}=2$ massless higher-spin theories in the harmonic superspace. The…
By using a Ginzburg-Landau functional in the Gaussian approximation, we calculate the energy of superconducting fluctuations above the transition, at zero external magnetic field, of a system composed by a small number $N$ of parallel…
We consider a model of nonlinear superfluid flow past a periodic array of point-like scatterers in one dimension. An application of this model is the determination of the critical current of a Josephson array in a regime appropriate to a…
Hybrid superconductor-semiconductor materials are fueling research in mesoscopic physics and quantum technology. Recently demonstrated smooth $\beta$-Sn superconductor shells, due to the increased induced gap, are expanding the available…
A Ginzburg-Landau theory is developed for unconventional superconductors with the three relevant singlet pairing channels. Various consequences of the sub-dominant channels (i.e., s- and d_{xy}-channels) are examined in detail. (1) In the…
Filling factor $\nu=1$ bilayer electron systems in the quantum Hall regime have an excitonic-condensate superfluid ground state when the layer separation $d$ is less than a critical value $d_c$. On a quantum Hall plateau current injected…
We consider the Ginzburg-Landau functional, defined on a two-dimensional simply connected domain with smooth boundary, in the situation when the applied magnetic field is piecewise constant with a jump discontinuity along a smooth curve. In…
Single-charge tunneling in ultrasmall voltage biased SIS junctions in a high-impedance electromagnetic environment is considered. The Cooper pair current is calculated at T=0 on the basis of the elementary tunnel Hamiltonian for…
The persistent current for a one-dimensional ring with two tunnel barriers is considered in the limit of weakly interacting electrons. In addition to a small off-resonance current, there are two kinds of resonant behavior; (i) a current…
Two rectangular models described by the one-dimensional Schroedinger equation with sharply localized potentials are suggested. The potentials have a multi-layer thin structure being composed from adjacent barriers and wells. Their peculiar…
In this work we consider a reduced Ginzburg-Landau model in which the magnetic field is neglected and the magnitude of the current density is significantly stronger than that considered in a recent work by the same authors. We prove the…
An explicit expression is obtained for the phase-time corresponding to tunneling of a (non-relativistic) particle through two rectangular barriers, both in the case of resonant and in the case of non-resonant tunneling. It is shown that the…
We investigate the shallow flow of viscous fluid into and out of a channel whose gap width increases as a power-law ($x^n$), where $x$ is the downstream axis. The fluid flows slowly, while injected at a rate in the form of $t^\alpha$, where…
We theoretically study the critical speed for superfluid flow of a two-dimensional miscible binary superfluid of light past a polarization-sensitive optical obstacle. This speed corresponds to the maximum mean flow velocity below which…