Phase Modulated Thermal Conductance of Josephson Weak Links

We present a theory for quasiparticle heat transport through superconducting weak links. The thermal conductance depends on the phase difference ($\phi$) of the superconducting leads. Branch conversion processes, low-energy Andreev bound states near the contact and the suppression of the local density of states near the gap edge are related to phase-sensitive transport processes. Theoretical results for the influence of junction transparency, temperature and disorder, on the phase modulation of the conductance are reported. For high-transmission weak links, $D\to 1$, the formation of an Andreev bound state at $\epsilon_{\text{\tiny b}}=\Delta\cos(\phi/2)$ leads to suppression of the density of states for the continuum excitations that transport heat, and thus, to a reduction in the conductance for $\phi\simeq\pi$. For low-transmission ($D\ll 1$) barriers resonant scattering at energies $\epsilon\simeq(1+D/2)\Delta$ leads to an increase in the thermal conductance as $T$ drops below $T_c$ (for phase differences near $\phi=\pi$).Comment: 4 pages, 3 figures Expanded discussion of boundary conditions for Ricatti amplitude

The internal Josephson effect in a Fermi gas near a Feshbach resonance

We consider a two-component system of Fermi atoms and molecular bosons in the vicinity of a Feshbash resonance. We derive an effective action for the system, which has a term describing coherent tunneling of the molecular bosons into Cooper pairs and vice versa. In the equilibrium state, global phase coherence may be destroyed by thermal or quantum phase fluctuations. In the non-equilibrium regime, the system may show an internal AC Josephson effect leading to real time oscillations in the number of molecular bosons.Comment: 5 pages, 2 figure

Tuning coherent-phonon heat transport in LaCoO3/SrTiO3 superlattices

Accessing the regime of coherent phonon propagation in nanostructures opens enormous possibilities to control the thermal conductivity in energy harvesting devices, phononic circuits, etc. In this paper we show that coherent phonons contribute substantially to the thermal conductivity of LaCoO3/SrTiO3 oxide superlattices, up to room temperature. We show that their contribution can be tuned through small variations of the superlattice periodicity, without changing the total superlattice thickness. Using this strategy, we tuned the thermal conductivity by 20% at room temperature. We also discuss the role of interface mixing and epitaxial relaxation as an extrinsic, material dependent key parameter for understanding the thermal conductivity of oxide superlattices. © 2021 The Authors. Published by American Chemical Society

Correction: Appetite disinhibition rather than hunger explains genetic effects on adult BMI trajectory

Correction to: International Journal of Obesity https://doi.org/10.1038/s41366-020-00735-9 The original version of this article unfortunately contained a mistake in the ESM. The original article has been corrected

Appetite disinhibition rather than hunger explains genetic effects on adult BMI trajectory

BACKGROUND/OBJECTIVES: The mediating role of eating behaviors in genetic susceptibility to weight gain during mid-adult life is not fully understood. This longitudinal study aims to help us understand contributions of genetic susceptibility and appetite to weight gain. SUBJECTS/METHODS: We followed the body-mass index (BMI) trajectories of 2464 adults from 45 to 65 years of age by measuring weight and height on four occasions at 5-year intervals. Genetic risk of obesity (gene risk score: GRS) was ascertained, comprising 92 BMI-associated single-nucleotide polymorphisms and split at a median (=high and low risk). At the baseline, the Eating Inventory was used to assess appetite-related traits of 'disinhibition', indicative of opportunistic eating or overeating and 'hunger' which is susceptibility to/ability to cope with the sensation of hunger. Roles of the GRS and two appetite-related scores for BMI trajectories were examined using a mixed model adjusted for the cohort effect and sex. RESULTS: Disinhibition was associated with higher BMI (β = 2.96; 95% CI: 2.66-3.25 kg/m2), and accounted for 34% of the genetically-linked BMI difference at age 45. Hunger was also associated with higher BMI (β = 1.20; 0.82-1.59 kg/m2) during mid-life and slightly steeper weight gain, but did not attenuate the effect of disinhibition. CONCLUSIONS: Appetite disinhibition is most likely to be a defining characteristic of genetic susceptibility to obesity. High levels of appetite disinhibition, rather than hunger, may underlie genetic vulnerability to obesogenic environments in two-thirds of the population of European ancestry

Commentary and Worked Examples to EN 1993-1-10 "Material Toughness and Through Thickness Properties" and Other Toughness Oriented Rules in EN 1993

This commentary gives explanations and worked examples to the design rules in Eurocode 3 that are influenced by the strength and toughness properties of the structural steels used. It is a commentary and background document to EN 1993-1-10 "Material toughness and through thickness properties" and its extension in EN 1993-1-12 "Design rules for high-strength steels", where toughness properties are explicitly addressed. It however provides also background to other parts of EN 1993, e.g. to EN 1993-1-1 "Design of steel structures - Basic rules and rules for buildings", where the design rules are related only to strength properties as the yield strength and the tensile strength without explicitly mentioning the role of toughness that is hidden behind the resistance formulae. Finally it gives some comments to chapter 6 of EN 1998-1: "Design of structures for earthquake resistance - Part 1: General rules, seismic actions and rules for buildings".JRC.G.5-European laboratory for structural assessmen

Nonequilibrium mesoscopic superconductors in a fluctuational regime

We show that there exist a class of nonequilibrium systems for which a non-equilibrium analog of the Ginzburg-Landau (GL) functional can be constructed and propose the procedure for its derivation. As an example, we consider a small superconductor island of the size less than the coherence length in a stationary nonequlibrium state. We find the GL expansion of the free energy functional of such a system and analyze the dependence of the coefficients of the expansion upon the external drive and the non-equilibrium distribution functions.Comment: 5 pages, 1 figur