Wire network behaviour of superconducting films with lower symmetrical mesoscopic hole arrays

Superconducting films with the same hole density but different geometric symmetry have been designed and fabricated. The R(H) curves show obvious periodic oscillations with several dips at fractional matching fields. It is found that the period of the oscillations in the low field is not necessary equal to that derived from the hole density, but consistent with that from the corresponding wire networks when the large disk-like film regions are regarded as nodes. The experimental results of R(H), T c (H) and j c (H) at fractional matching fields within the first oscillation also support the rationality of considering films with large-diametered hole arrays as wire networks. Our results demonstrate that the connectivity of superconducting films with large-diametered hole arrays plays a more important role in the oscillations of R(H) curves.

Effects of the Tensor Force on the Ground Properties of Zr Isotopes

The effects of the tensor force on the ground properties of Zr isotopes are studied in the framework of the Skyrme–Hartree–Fock approach. It is found that the tensor force strongly affects the ground state energies and the geometric symmetry properties, in particular for those isotopes near N=60 region. The effects are attributed to the fact that the tensor force enlarges the spin and pseudospin symmetry breaking and therefore results in a ∼2 MeV sub-shell gap between d3/2 and s1/2 single-particle levels.

Geometry symmetry-free and higher-order optical bound states in the continuum

Geometrical symmetry plays a significant role in implementing robust, symmetry-protected, bound states in the continuum (BICs). However, this benefit is only theoretical in many cases since fabricated samples’ unavoidable imperfections may easily break the stringent geometrical requirements. Here we propose an approach by introducing the concept of geometrical-symmetry-free but symmetry-protected BICs, realized using the static-like environment induced by a zero-index metamaterial (ZIM). We find that robust BICs exist and are protected from the disordered distribution of multiple objects inside the ZIM host by its physical symmetries rather than geometrical ones. The geometric-symmetry-free BICs are robust, regardless of the objects’ external shapes and material parameters in the ZIM host. We further show theoretically and numerically that the existence of those higher-order BICs depends only on the number of objects. By practically designing a structural ZIM waveguide, the existence of BICs is numerically confirmed, as well as their independence on the presence of geometrical symmetry. Our findings provide a way of realizing higher-order BICs and link their properties to the disorder of photonic systems.

The geometry, branes and applications of exceptional field theory

This is a review of exceptional field theory: a generalisation of Kaluza–Klein theory that unifies the metric and [Formula: see text]-form gauge field degrees of freedom of supergravity into a generalised or extended geometry, whose additional coordinates may be viewed as conjugate to brane winding modes. This unifies the maximal supergravities, treating their previously hidden exceptional Lie symmetries as a fundamental geometric symmetry. Duality orbits of solutions simplify into single objects, that in many cases have simple geometric interpretations, for instance as wave or monopole-type solutions. It also provides a route to explore exotic or nongeometric aspects of M-theory, such as exotic branes, [Formula: see text]-folds, and more novel sorts of non-Riemannian spaces.

Properties of inertia of a solid body

Definitions are given and properties of inertial characteristics of solid are formulated; the influence of geometric symmetry of the body on its characteristics is described. The geometric approach to the presentation of the material is used.

Geometrization of heat conduction in perturbative space–times

We prove that the problem of symmetry determination linked to first-order perturbations of a metric, can be elegantly expressed using geometric conditions. In particular, an important feature of this study is that for any space–time that contains small perturbations, any equation constructed on such a space will inherit the perturbations. Intrigued by this connection between geometry and perturbations, we take the heat conduction equation and explore how the inherited perturbations affect the geometric symmetry conditions.

3D low toxicity Cu–Pb binary perovskite films and their photoluminescent/photovoltaic performance

The 3D low-toxic Cu–Pb binary perovskite films with improved geometric symmetry and typical 2 μm grain size have been prepared, which can achieve a six fold increase in PL intensity and a PCE of 5.1% with suppressed hysteresis for planar solar cells.