Topological phase transition and two dimensional topological insulators in Ge-based thin films

We discuss possible topological phase transitions in Ge-based thin films of Ge(Bi$_x$Sb$_{1-x}$)$_2$Te$_4$ as a function of layer thickness and Bi concentration $x$ using the first principles density functional theory framework. The bulk material is a topological insulator at $x$ = 1.0 with a single Dirac cone surface state at the surface Brillouin zone center, whereas it is a trivial insulator at $x$ = 0. Through a systematic examination of the band topologies we predict that thin films of Ge(Bi$_x$Sb$_{1-x}$)$_2$Te$_4$ with $x$ = 0.6, 0.8 and 1.0 are candidates for two-dimensional (2D) topological insulators, which would undergo a 2D topological phase transition as a function of $x$. A topological phase diagram for Ge(Bi$_x$Sb$_{1-x}$)$_2$Te$_4$ thin films is presented to help guide their experimental exploration.Comment: 7 pages, 5 figures, Accepted for publication in Physical Review B (2012

Creatinium hydrogen oxalate

The crystal structure of the title compound, C4H10N3O2 +·C2HO4 −, is stabilized by N—H⋯O and O—H⋯O hydrogen bonds. The anions are connected by an O—H⋯O hydrogen bond, leading to C(5) chain extending along c axis. The cations are dimerized around the corners of the unit cell, leading to an R 2 2(14) ring motif. This leads to a cationic mol­ecular aggregation at x = 0 or 1 and an anionic mol­ecular aggregation at x = 1/2

Creatininium cinnamate

The crystal structure of the title compound (systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 3-phenyl­prop-2-enoate), C4H8N3O+·C9H7O2 −, is stabilized by N—H⋯O hydrogen bonding. Cations are linked to anions to form ion pairs with an R 2 2(8) ring motif. These ion pairs are connected through a C 2 2(6) chain motif extending along the c axis of the unit cell. This crystal packing is characterized by hydro­phobic layers at x ∼ 1/2 packed between hydro­philic layers at x ∼ 0

Creatininium 2-chloro­acetate

In the title compound (systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 2-chloro­acetate), C4H8N3O+·C2H2ClO2 −, the mol­ecular aggregations are stabil­ized through classical (N—H⋯O) and non-classical (C—H⋯O and C—H⋯N) hydrogen-bonding inter­actions. The cations are linked to the anions, forming ion pairs through two N—H⋯O bonds that produce characteristic R 2 2(8) ring motifs. These cation–anion pairs are connected through another N—H⋯O hydrogen bond, leading to an R 4 2(8) ring motif. Further weak C—H⋯N inter­actions link the mol­ecules along the a axis, while other C—H⋯O inter­actions generate zigzag chains extending along b

"The Financial Requirements of Achieving Gender Equality and Women's Empowerment"

Although the Millennium Development Goals (MDGs) have been ratified in global and national forums, they have not yet been incorporated into operational planning within governments or international organizations. The weak link between the policies and the investments needed for their implementation is one barrier to progress. An assessment of the resources required is a critical first step in formulating and implementing strategies to achieve the MDGs. This is especially true for policies to promote gender equality and empower women. Although enough is known about such policies to implement them successfully, the costs of such interventions are not systematically calculated and integrated into country-level budgeting processes. Using country-level data, the paper estimates the costs of interventions aimed at promoting gender equality and women's empowerment in Bangladesh, Cambodia, Ghana, Tanzania, and Uganda. It then uses these estimates to calculate the costs of such interventions in other low-income countries. Finally, the paper projects the financing gap for interventions that aim directly at achieving gender equality, first for the five countries, and subsequently for all low-income countries.

Two quantum analogues of Fisher information from a large deviation viewpoint of quantum estimation

We discuss two quantum analogues of Fisher information, symmetric logarithmic derivative (SLD) Fisher information and Kubo-Mori-Bogoljubov (KMB) Fisher information from a large deviation viewpoint of quantum estimation and prove that the former gives the true bound and the latter gives the bound of consistent superefficient estimators. In another comparison, it is shown that the difference between them is characterized by the change of the order of limits.Comment: LaTeX with iopart.cls, iopart12.clo, iopams.st

Creatininium hydrogen maleate

In the title compound, C4H8N3O+·C4H3O4 −, the cations and anions are linked through N—H⋯O hydrogen bonds making a ionic pair with an R 2 2(8) ring motif. These ionic pairs are further connected through another N—H⋯O hydrogen bond, leading to an R 6 6(16) ring motif around the inversion centres of the unit cell. These approximately planar aggregates are further connected through weak van der Waals inter­actions in the unit cell. The anions have a characteristic intra­molecular O—H⋯O hydrogen bond with a self-associated ring S(7) motif