Staphylinidae from Under Bark and at Sap of Trees, a Preliminary Survey of Species Possibly Beneficial to Forestry (Coleoptera)

Two hundred and one species of Staphylinidae known to be found under bark or at sap of trees are listed. The possibility of these insects being important elements in the population dynamics of forest pests is discussed. An indication is given of the distribution and habitat of each species

Topological invariants, surface states, and interaction-driven phase transitions in correlated Kondo insulators with cubic symmetry

We construct a lattice model for a cubic Kondo insulator consisting of one spin-degenerate $d$ and $f$ orbital at each lattice site. The odd-parity hybridization between the two orbitals permits us to obtain various trivial and topological insulating phases, which we classify in the presence of cubic symmetry. In particular, depending on the choice of our model parameters, we find a strong topological insulator phase with a band inversion at the $\mathrm{X}$ point, modeling the situation potentially realized in SmB$_6$, and a topological crystalline insulator phase with trivial $\mathbb{Z}_2$ indices but nonvanishing mirror Chern numbers. Using the Kotliar-Ruckenstein slave-boson scheme, we further demonstrate how increasing interactions among $f$ electrons can lead to topological phase transitions. Remarkably, for fixed band parameters, the $f$-orbital occupation number at the topological transitions is essentially independent of the interaction strength, thus yielding a robust criterion to discriminate between different phases.Comment: 15 pages, 13 figure

Relating the entanglement spectrum of noninteracting band insulators to their quantum geometry and topology

We study the entanglement spectrum of noninteracting band insulators, which can be computed from the two-point correlation function, when restricted to one part of the system. In particular, we analyze a type of partitioning of the system that maintains its full translational symmetry, by tracing over a subset of local degrees of freedom, such as sublattice sites or spin orientations. The corresponding single-particle entanglement spectrum is the band structure of an entanglement Hamiltonian in the Brillouin zone. We find that the hallmark of a nontrivial topological phase is a gapless entanglement spectrum with an "entanglement Fermi surface." Furthermore, we derive a relation between the entanglement spectrum and the quantum geometry of Bloch states contained in the Fubini-Study metric. The results are illustrated with lattice models of Chern insulators and Z_2 topological insulators.Comment: 10 pages, 4 figure

Towards comparable business model concepts: resource description framework (RDF) schemas for semantic business model representations

Scholars have demonstrated that business model (BM) choices have a significant impact on the success of products, innovations and organizations. However, knowledge about key elements of BMs is disseminated across a large body of literature and builds on different conceptualizations. We take a step back and provide a new approach to formalize BM concepts and related BM knowledge, based on concepts from the semantic web. We introduce and evaluate the Resource Description Framework (RDF) as a data model for comparable and extensible BM descriptions. Moreover, we use this new perspective to analyze commonalities and differences between BM concepts, to reflect critically on the process of translating concepts to RDF and evaluate its relevance for BM design practice

Circular dichroism and bilayer splitting in the normal state of underdoped (Pb,Bi)2_2Sr2_2(Cax_xY1−x_{1-x})Cu2_2O8+δ_{8+\delta} and overdoped (Pb,Bi)2_2Sr2_2CaCu2_2O8+δ_{8+\delta}

We report an ARPES investigation of the circular dichroism in the first Brillouin zone (BZ) of under- and overdoped Pb-Bi2212 samples. We show that the dichroism has opposite signs for bonding and antibonding components of the bilayer-split CuO-band and is antisymmetric with respect to reflections in both mirror planes parallel to the c-axis. Using this property of the energy and momentum intensity distributions we prove the existence of the bilayer splitting in the normal state of the underdoped compound and compare its value with the splitting in overdoped sample. In agreement with previous studies the magnitude of the interlayer coupling does not depend significantly on doping. We also discuss possible origins of the observed dichroism.Comment: 4 RevTex pages, 4 EPS figure