Confined magnetic guiding orbit states

We show how snake-orbit states which run along a magnetic edge can be confined electrically. We consider a two-dimensional electron gas (2DEG) confined into a quantum wire, subjected to a strong perpendicular and steplike magnetic field $B/-B$. Close to this magnetic step new, spatially confined bound states arise as a result of the lateral confinement and the magnetic field step. The number of states, with energy below the first Landau level, increases as $B$ becomes stronger or as the wire width becomes larger. These bound states can be understood as an interference between two counter-propagating one-dimensional snake-orbit states.Comment: 4 pages, 4 figure

The Dorsa Argentea, Mars: New Comparisons to a Large Sample of Terrestrial Eskers and Quantitative Tests for Esker-Like Topographic Relationships

The Dorsa Argentea (DA) are an assemblage of ridges in Mars’ southern high latitudes (70°-80°S, 56°W-6°E). Glacial eskers and inverted channels remain as active hypotheses for their formation. The esker interpretation is widely used as a basis for reconstructions of meltwater production beneath a putative former ice sheet in the region of the DA during Mars’ Hesperian period, despite a lack of rigorous quantitative testing of the esker hypothesis. We undertake the first large-scale quantitative analysis of the plan view geometries of the DA in a comparison to >5900 terrestrial esker systems in Canada. Statistical tests for esker-like topographic relationships are also completed. Our results support the esker hypothesis and highlight that future studies of the DA and its parent ice sheet should more closely consider the ongoing debate over the spatio-temporal nature of terrestrial esker formation, and its implications for reconstructions of ice sheet meltwater production

1-[3-(2,4-Dichloro-5-fluoro­phen­yl)-5-(3-methyl-2-thien­yl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone

In the title mol­ecule, C16H13Cl2FN2OS, the dihedral angle between the thio­phene and benzene rings is 80.34 (12)°. The pyrazoline ring is in an envelope conformation, and the plane through the four coplanar atoms makes dihedral angles of 85.13 (9) and 6.89 (10)° with the thio­phene and benzene rings, respectively. The C and O atoms of the acetyl group are nearly coplanar with the attached pyrazoline ring. In the crystal structure, inversion dimers arise from pairs of inter­molecular C—H⋯O hydrogen bonds. A short inter­molecular Cl⋯S contact of 3.4250 (13) Å is also found

Structure of multiphoton quantum optics. II. Bipartite systems, physical processes, and heterodyne squeezed states

Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper ``Structure of multiphoton quantum optics. I. Canonical formalism and homodyne squeezed states'', we introduce two-mode nonlinear canonical transformations depending on two heterodyne mixing angles. They are defined in terms of hermitian nonlinear functions that realize heterodyne superpositions of conjugate quadratures of bipartite systems. The canonical transformations diagonalize a class of Hamiltonians describing non degenerate and degenerate multiphoton processes. We determine the coherent states associated to the canonical transformations, which generalize the non degenerate two--photon squeezed states. Such heterodyne multiphoton squeezed are defined as the simultaneous eigenstates of the transformed, coupled annihilation operators. They are generated by nonlinear unitary evolutions acting on two-mode squeezed states. They are non Gaussian, highly non classical, entangled states. For a quadratic nonlinearity the heterodyne multiphoton squeezed states define two--mode cubic phase states. The statistical properties of these states can be widely adjusted by tuning the heterodyne mixing angles, the phases of the nonlinear couplings, as well as the strength of the nonlinearity. For quadratic nonlinearity, we study the higher-order contributions to the susceptibility in nonlinear media and we suggest possible experimental realizations of multiphoton conversion processes generating the cubic-phase heterodyne squeezed states.Comment: 16 pages, 23 figure

4,5-Dimethyl-2-phenyl-1-(p-tol­yl)-1H-imidazole

In the title compound, C18H18N2, the imidazole ring is essentially planar [maximum deviation = 0.004 (1) Å] and makes dihedral angles of 68.91 (8) and 20.43 (9)° with the tolyl and phenyl rings, respectively. The dihedral angle between the latter rings is 73.62 (8)°. The crystal packing is stabilized by inter­molecular C—H⋯N hydrogen bonds

1-(3,5-Dimethyl­phen­yl)-4,5-dimethyl-2-phenyl-1H-imidazole hemihydrate

In the title compound, C19H20N2·0.5H2O, the imidazole ring is essentially planar [maximum deviation = 0.005 (1) Å]. The imidazole ring makes dihedral angles of 67.46 (10) and 23.10 (11)° with the attached benzene and phenyl rings, respectively. The dihedral angle between the benzene and phenyl rings is 68.22 (10)°. Inter­molecular O—H⋯N and C—H⋯N hydrogen bonds are found in the crystal structure

Evidence for Recent Wet-Based Crater Glaciation in Tempe Terra, Mars.

[Introduction] Mars’ mid-latitudes host abundant putative debris-covered water-ice glaciers (viscous flow features; VFF). Eskers emerging from 110-150 Myr-old VFF in Phlegra Montes and Tempe Terra provide evidence for rare occurences of past, localized basal melting of their parent VFF, despite the cold climates of the late Amazonian (see this conf.). Eskers are sinuous ridges comprising glaciofluvial sediment deposited by meltwater flowing through tunnels within glacial ice. Here, we describe a population of sinuous ridges emerging from VFF in an unnamed ~45 km-diameter crater (38.47 N, 72.43 W) in Tempe Terra, ~600 km from the VFF-linked esker identified by Butcher et al. We consider two working hypotheses for the formation of the sinuous ridges; that they are either (1) eskers formed by melting of the glaciers from which they emerge, or (2) topographically inverted fluvial channels which formed prior to glaciation of the crater. We present observations from preliminary geomorphic mapping of the crater to start to test those hypotheses

N′-(2-Methyl-3-phenyl­allyl­idene)nicotinohydrazide monohydrate

The asymmetric unit of the title compound, C16H15N3O·H2O, contains an N′-(2-methyl-3-phenyl­allyl­idene)nicotino­hydra­zide mol­ecule and a water solvent mol­ecule. The dihedral angle between the pyridine ring and the phenyl ring is 47.26 (5)°. Inter­molecular O—H⋯N, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds are found in the crystal structure. Furthermore, C—H⋯π inter­actions involving the pyridine and phenyl rings are also found