maxLik: A package for maximum likelihood estimation in R

This paper describes the package maxLik for the statistical environment R. The package is essentially a unified wrapper interface to various optimization routines, offering easy access to likelihood-specific features like standard errors or information matrix equality (BHHH method). More advanced features of the optimization algorithms, such as forcing the value of a particular parameter to be fixed, are also supported.     

A new antiferromagnetic phase in EuSe below 1.8 K

Dilatometric and magnetic measurements gave evidence of a new antiferromagnetic phase in EuSe. This phase occurs below 1.8 K in external magnetic fields smaller than 500 oe. Presumably the spin structure of this phase is of the MnO-type. The strains accompanying the magnetic transitions in EuSe have been measured. Furthermore a change of the magnetocrystalline anisotropy constants has been observed at 2.8 K.     

Synthesis of deutero analogs of α-methyl-2,3,4,6-tetra-O-methyl-D-glucopyranoside

Conclusions The 1d-, 2d-, 3d-, 4d-, 5d-, and 6d₂--methyl-2,3,4,6-tetra-O-methyl-D-glucopyranosides, containing over 90% of deuterium were synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 201–204, January, 1977.     

Spectroscopy of stripe order in La1.8Sr0.2NiO4 using resonant soft x-ray diffraction

Strong resonant enhancements of the charge-order and spin-order superstructure-diffraction intensities in La1.8Sr0.2NiO4 are observed when x-ray energies in the vicinity of the Ni L2,3 absorption edges are used. The pronounced photon-energy and polarization dependences of these diffraction intensities allow for a critical determination of the local symmetry of the ordered spin and charge carriers. We found that not only the antiferromagnetic order but also the charge-order superstructure resides within the NiO2 layers; the holes are mainly located on in-plane oxygens surrounding a Ni2+ site with the spins coupled antiparallel in close analogy to Zhang-Rice singlets in the cuprates.     

Radio frequency selective addressing of localized atoms in a periodic potential

We study the localization and addressability of ultracold atoms in a combined parabolic and periodic potential. Such a potential supports the existence of localized stationary states and we show that applying a radio frequency field allows us to selectively address atoms in these states. This method is used to measure the energy and momentum distribution of the atoms in the localized states. We also discuss possible extensions of this scheme to address and manipulate atoms in single lattice sites.