Universal Properties of Fermi Gases in One-dimension

In this Rapid Communication, we investigate the universal properties of a spin-polarized two-component Fermi gas in one dimension (1D) using Bethe ansatz. We discuss the quantum phases and phase transitions by obtaining exact results for the equation of state, the contact, the magnetic susceptibility and the contact susceptibility, giving a precise understanding of the 1D analogue of the Bose-Einstein condensation and Bardeen-Cooper-Schrieffer crossover in three dimension (3D) and the associated universal magnetic properties. In particular, we obtain the exact form of the magnetic susceptibility $\chi \sim {1}/{\sqrt{T}}\exp(-\Delta/T)$ at low temperatures, where $\Delta$ is the energy gap and $T$ is the temperature. Moreover, we establish exact upper and lower bounds for the relation between polarization $P$ and the contact $C$ for both repulsive and attractive Fermi gases. Our findings emphasize the role of the pair fluctuations in strongly interacting 1D fermion systems that can shed light on higher dimensions.Comment: 4 figures, the main pape

Geometry Dependent Current-Voltage Characteristics of ZnO Nanostructures: A Combined Nonequilibrium Green’s Function and Density Functional Theory Study

Current-voltage I-V characteristics of different ZnO nanostructures were studied using a combined nonequilibrium Green’s function and density functional theory techniques with the two-probe model. It was found that I-V characteristics of ZnO nanostructures depend strongly on their geometry. For wurtzite ZnO nanowires, currents decrease with increasing lengths under the same applied voltage conditions. The I-V characteristics are similar for single-walled ZnO nanotubes and triangular cross section ZnO nanowires but they are different from I-V characteristics of hexagonal cross section ZnO nanowires. Finally, our results are discussed in the context of calculated transmission spectra and densities of states

Tetra-μ-acetato-κ8 O:O′-bis­{[2-methyl­sulfanyl-4-(pyridin-4-yl-κN)pyrimidine]­copper(II)}(Cu—Cu)

The binuclear title compound, [Cu2(CH3CO2)4(C10H9N3S)2], comprises a Cu2(CH3CO2)4 paddle-wheel core axially bound by two 2-methyl­sulfanyl-4-(pyridin-4-yl)pyrimidine ligands. The complex mol­ecule has an inversion center lying at the mid-point of the Cu—Cu bond