4,734 research outputs found
Extended staggered-flux phases in two-dimensional lattices
Based on the so called - model in two-dimensional (2D) lattices, we
investigate the stabilities of a class of extended staggered-flux (SF) phases
(which are the extensions of the SF phase to
generalized spatial periods) against the Fermi-liquid phase. Surprisingly, when
away from the nesting electron filling, some extended-SF phases take over the
dominant SF phase (the SF phase for the square
lattice, a SF phase for the triangular one), compete with the
Fermi-liquid phase in nontrivial patterns, and still occupy significant space
in the phase diagram through the advantage in the total electronic kinetic
energies. The results can be termed as the generalized Perierls
orbital-antiferromagnetic instabilities of the Fermi-liquid phase in 2D
lattice-electron models.Comment: 5 pages, 5 figure
Multiple Fermi pockets revealed by Shubnikov-de Haas oscillations in WTe2
We use magneto-transport measurements to investigate the electronic structure
of WTe2 single crystals. A non-saturating and parabolic magnetoresistance is
observed in the temperature range between 2.5 to 200 K and magnetic fields up
to 8 T. Shubnikov - de Haas oscillations with beating patterns are observed.
The fast Fourier transform of the SdH oscillations reveals three oscillation
frequencies, corresponding to three pairs of Fermi pockets with comparable
effective masses , m* ~ 0.31 me. By fitting the Hall resistivity, we infer the
presence of one pair of electron pockets and two pairs of hole pockets,
together with nearly perfect compensation of the electron-hole carrier
concentration. These magnetotransport measurements reveal the complex
electronic structure in WTe2, explaining the nonsaturating magnetoresistance.Comment: Submitted to journal on 1 April, 2015, 4 Figure
2-Methyl-2,4-di-4-pyridyl-2,3-dihydro-1H-1,5-benzodiazepine acetic acid solvate
In the title compound, C20H18N4·CH3COOH, the benzene ring forms dihedral angles of 81.34 (11) and 54.32 (11)° with the two pyridine rings. In the crystal, intermolecular O—H⋯N hydrogen bonding links one 1,5-benzodiazepine molecule and one acetic acid solvent molecule into a dimer. These dimers, related by translation along the b axis, are further linked into chains via weak intermolecular N—H⋯N hydrogen bonds
2,2,2-Trifluoroethyl 4-methylbenzenesulfonate
In the crystal structure of the title compound, C9H9F3O3S, intermolecular C—H⋯O hydrogen bonds link the molecules along the c-axis direction. Also present are slipped π–π stacking interactions between phenylene rings, with perpendicular interplanar distances of 3.55 (2) Å and centroid–centroid distances of 3.851 (2) Å
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