相关论文: Quantum phase slips in a confined geometry

We develop a computational model of quantum turbulence decay employing a kinematic prescription for the normal fluid. We find that after an initial transient, the length of the vortex tangle L decreases and for large times obeys a scaling…

In certain materials with strong electron correlations a quantum phase transition (QPT) at zero temperature can occur, in the proximity of which a quantum critical state of matter has been anticipated. This possibility has recently…

We report transport measurements on a semiconductor quantum dot with a small number of confined electrons. In the Coulomb blockade regime, conduction is dominated by cotunneling processes. These can be either elastic or inelastic, depending…

The sharp drops in the resistance and magnetization which are usually attributed to a phase transition from the vortex liquid state to a crystal state are explained instead as a crossover between three and two dimensional behavior, which…

Coherent Quantum Phase Slip consists in the coherent transfer of vortices in superfluids. We investigate this phenomenon in two miscible coherently coupled components of a spinor Bose gas confined in a toroidal trap. After imprinting…

The study of topological superconductivity is largely based on the analysis of simple mean-field models that do not conserve particle number. A major open question in the field is whether the remarkable properties of these mean-field models…

We have studied quantization and confinement effects in nanostructured superconductors. Three different types of nanostructured samples were investigated: individual structures (line, loop, dot), 1-dimensional (1D) clusters of loops and 2D…

The spatial distribution of the differential conductance for ultrathin Pb films grown on Si(111)7x7 substrate is studied by means of low-temperature scanning tunneling microscopy and spectroscopy. The formation of the quantum--confined…

A new approach to the treatment of magnetic fluctuations in thin films of type I superconductors is introduced. Results for the dependence of free energy, specific heat and order parameter profile on the film thickness near the equilibrium…

The effect of electrostatic gating on metallic elemental superconductors was recently demonstrated in terms of modulation of the switching current and control of the current phase relation in superconducting quantum interferometers. The…

In superconducting qubits the lifetime of quantum states cannot be prolonged arbitrarily by decreasing temperature. At low temperature quasiparticles tunneling between electromagnetic environment and superconducting islands takes the…

We carry out Monte Carlo simulations of the uniformly frustrated 3d XY model as a model for vortex line fluctuations in a high Tc superconductor. A density of vortex lines of f=1/25 is considered. We find two sharp phase transitions. The…

Two-dimensional superconductors offer an excellent platform for the study of vortex matter due to their low superfluid stiffness and inability to effectively screen applied magnetic fields. Here we explore vortices in a two-dimensional…

We study tunneling of electrons into and between interacting wires in the spin-incoherent regime subject to a magnetic field. The tunneling currents follow power laws of the applied voltage with exponents that depend on whether the electron…

We present here a simple qualitative model that interpolates between the high and low temperature properties of quasi-1D conductors. At high temperatures we argue that transport is governed by inelastic scattering whereas at low…

An one-dimensional model of magnetic flux penetration into thin strip-like superconductive film is subject to numerical analysis which combines explicit account for specific oblate geometry of magnetic field lines around the film and a…

We report measurements on ultrathin (<10 nm) nanowires produced by coating carbon nanotubes with a superconducting amorphous MoGe alloy. We find that nanowires can be superconducting or insulating depending on their normal state resistance…

We reply to the recent Comment [cond-mat/9702231] by J.-M. Duan. Our point of view is markedly different on every issue raised. Much of the disagreement can be traced to a different preception of experimentally relevant length scales. i) We…

The thermodynamic properties of the superconducting state in the amorphous ${\rm Sn_{1-x}Cu_{x}}$ thin films have been characterized. The concentration of copper changes in the range from $0.08$ to $0.41$. The calculations have been…

We consider a system of superconducting grains embedded in a normal metal. At zero temperature this system exhibits a quantum superconductor-normal metal phase transition. This transition can take place at arbitrarily large conductance of…