64 research outputs found
Topological order in Josephson junction ladders with Mobius boundary conditions
We propose a CFT description for a closed one-dimensional fully frustrated
ladder of quantum Josephson junctions with Mobius boundary conditions, in
particular we show how such a system can develop topological order. Such a
property is crucial for its implementation as a "protected" solid state qubit.Comment: 14 pages, 3 figures, to appear in JSTA
Quantum Vacuum Contribution to the Momentum of the Dielectric Media
Momentum transfer between matter and electromagnetic field is analyzed. The
related equations of motion and conservation laws are derived using
relativistic formalism. Their correspondence to various, at first sight
self-contradicting, experimental data (the so called Abraham-Minkowski
controversy) is demonstrated. A new, Casimir like, quantum phenomenon is
predicted: contribution of vacuum fluctuations to the motion of dielectric
liquids in crossed electric and magnetic fields. Velocities about can
be expected due to the contribution of high frequency vacuum modes
Tunneling of a Quantized Vortex: Roles of Pinning and Dissipation
We have performed a theoretical study of the effects of pinning potential and
dissipation on vortex tunneling in superconductors. Analytical results are
obtained in various limits relevant to experiment. In general we have found
that pinning and dissipation tend to suppress the effect of the vortex velocity
dependent part of the Magnus force on vortex tunneling.Comment: Latex, 12 page
Learning and innovative elements of strategy adoption rules expand cooperative network topologies
Cooperation plays a key role in the evolution of complex systems. However,
the level of cooperation extensively varies with the topology of agent networks
in the widely used models of repeated games. Here we show that cooperation
remains rather stable by applying the reinforcement learning strategy adoption
rule, Q-learning on a variety of random, regular, small-word, scale-free and
modular network models in repeated, multi-agent Prisoners Dilemma and Hawk-Dove
games. Furthermore, we found that using the above model systems other long-term
learning strategy adoption rules also promote cooperation, while introducing a
low level of noise (as a model of innovation) to the strategy adoption rules
makes the level of cooperation less dependent on the actual network topology.
Our results demonstrate that long-term learning and random elements in the
strategy adoption rules, when acting together, extend the range of network
topologies enabling the development of cooperation at a wider range of costs
and temptations. These results suggest that a balanced duo of learning and
innovation may help to preserve cooperation during the re-organization of
real-world networks, and may play a prominent role in the evolution of
self-organizing, complex systems.Comment: 14 pages, 3 Figures + a Supplementary Material with 25 pages, 3
Tables, 12 Figures and 116 reference
Nat Genet
The function of the majority of genes in the mouse and human genomes remains unknown. The mouse embryonic stem cell knockout resource provides a basis for the characterization of relationships between genes and phenotypes. The EUMODIC consortium developed and validated robust methodologies for the broad-based phenotyping of knockouts through a pipeline comprising 20 disease-oriented platforms. We developed new statistical methods for pipeline design and data analysis aimed at detecting reproducible phenotypes with high power. We acquired phenotype data from 449 mutant alleles, representing 320 unique genes, of which half had no previous functional annotation. We captured data from over 27,000 mice, finding that 83% of the mutant lines are phenodeviant, with 65% demonstrating pleiotropy. Surprisingly, we found significant differences in phenotype annotation according to zygosity. New phenotypes were uncovered for many genes with previously unknown function, providing a powerful basis for hypothesis generation and further investigation in diverse systems.Comment in : Genetic differential calculus. [Nat Genet. 2015]
Comment in : Scaling up phenotyping studies. [Nat Biotechnol. 2015
Mesoscopics in vortex core: level statistics and transport properties
Abstract Dissipation due to vortex motion in a strongly anisotropic type-II superconductor at low temperatures is studied. We focus on the moderately clean case of D 2 rE < t y1 < D and consider the low-velocity limit where dissipation is due to F Ž . the Landau-Zener transitions. It is shown that the flux-flow I V characteristic in the mixed state of a weakly coupled layered-superconductor can contain hysteretic branch, contrary to the cases of purely 2D and 3D superconductors. q 2000 Elsevier Science B.V. All rights reserved
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