1,215 research outputs found
Josephson Effect in a Coulomb-blockaded SINIS Junction
The problem of Josephson current through Coulomb-blocked nanoscale
superconductor-normal-superconductor structure with tunnel contacts is
reconsidered. Two different contributions to the phase-biased supercurrent are
identified, which are dominant in the limits of weak and strong Coulomb
interaction. Full expression for the free energy valid at arbitrary Coulomb
strength is found. The current derived from this free energy interpolates
between known results for weak and strong Coulomb interaction as phase bias
changes from 0 to pi. In the broad range of Coulomb strength the current-phase
relation is substantially non-sinusoidal and qualitatively different from the
case of semi-ballistic SNS junctions. Coulomb interaction leads to appearance
of a local minimum in the current at some intermediate value of phase
difference applied to the junction.Comment: 5 pages, 2 EPS figures, JETP Letters style file include
Correlations of the local density of states in quasi-one-dimensional wires
We report a calculation of the correlation function of the local density of
states in a disordered quasi-one-dimensional wire in the unitary symmetry class
at a small energy difference. Using an expression from the supersymmetric
sigma-model, we obtain the full dependence of the two-point correlation
function on the distance between the points. In the limit of zero energy
difference, our calculation reproduces the statistics of a single localized
wave function. At logarithmically large distances of the order of the Mott
scale, we obtain a reentrant behavior similar to that in strictly
one-dimensional chains.Comment: Published version. Minor technical and notational improvements. 16
pages, 1 figur
Up against a Wall: Europe’s Options for Regulating Biotechnology through Regulatory Anarchy
Based on the current state of EU law and the political sentiment surrounding Genetically Modified Organisms, this paper argues that the best approach to regulating the import and export of GMOs into the Community and between Member States is by what I will call for the purposes of this Paper “regulatory anarchy.” This system sits in opposition to a hierarchical regulatory approach which may be associated with traditional neo-functionalist theories of Community integration. Applied in the context of GMOs, regulatory anarchy envisions integration not coming solely from Community rules conceived by the Commission, but by Member State negotiated rules accomplished at the level of regulatory civil servants negotiating among each other. Greater centralization will occur in the regulation of GMOs because the risk of defection in this area by an individual regulatory body imposes very high costs on other national regulators, to the point where they are willing to relinquish some of their own enforcement authority for assurances against collective action problems. Due to the current gridlock caused by recalcitrant Member States, the GMO regime may be more effectively and efficiently handled by a system that employs regulatory anarchy; whereby twenty-five interested parties are initially brought to the table to approve a release (rather than one Member State), leaving less opportunities for regulatory capture by one Member State and still leaving room for Community supervision
- …