Properties of high-numerical-aperture Mueller-matrix polarimeters

To our knowledge there has been very little work done to establish the theoretical basis of high-NA Mueller matrix polarimetry. We consider how high-NA polarimetry differs from traditional wide-field polarimetry. We show that confocal polarimetry leads to an averaging of the sample Jones matrices, each of which is associated with one of the incident plane waves comprising the incident focused field and that a conventional polarimeter leads to an averaging of sample Mueller matrices. We conclude with an example.     

Quantum measurement with chaotic apparatus

We study a dissipative quantum mechanical model of the projective measurement of a qubit. We demonstrate how a correspondence limit, damped quantum oscillator can realise chaotic-like or periodic trajectories that emerge in sympathy with the projection of the qubit state, providing a model of the measurement process.     

EXAFS studies of the local environment of lead and selenium atoms in PbTe1−x Sex solid solutions

EXAFS spectroscopy is used to study the local environment of lead and selenium atoms in PbTe_1−x Se_x solid solutions. In addition to a bimodal distribution of the bond lengths in the first-coordination sphere, an unusually large value of the Debye-Waller factors for the Pb-Pb interatomic distances (second-coordination sphere) and a substantial deviation of this value from Vegard’s law are observed. Monte Carlo calculations show that these observations are related to the complicated structure of the distribution function for Pb-Pb distances. It is found that the number of Se-Se pairs in the second-coordination sphere exceeds the statistical value, which indicates that chemical factors play an important role in the structure of the solid solutions. The contribution of chemical factors to the enthalpy of mixing of the solid solution is estimated (≈0.5 kcal/mole) and this value is shown to be comparable to the deformation contribution. Fiz. Tverd. Tela (St. Petersburg) 41, 1394–1402 (August 1999)     

[Fe(TPP)(4‐MePip)2]: an axially compressed bis­(secondary amine) complex of an iron(II) porphyrin

The low‐spin iron(II) ion of bis(4‐methyl­piperidine)(5,10,15,20‐tetra­phenyl­porphyrinato)­iron(II), [Fe(TPP)(4‐MePip)₂], where TPP is 5,10,15,20‐tetra­phenyl­porphyrinate (C₄₄H₂₈N₄) and 4‐MePip is 4‐methyl­piperidine (C₆H₁₃N), is located at a center of inversion, and there is one mol­ecule in the triclinic unit cell. The axial 4‐MePip ligands adopt a chair conformation and the α‐C atoms are oriented at angles of 21.2 (2) and 32.8 (2)° relative to the closest porphyrin N atoms. The equatorial Fe—N_TPP distances are 1.998 (2) and 1.990 (2) Å, while the axial Fe—N distance is 2.107 (2) Å. The relatively short axial coordination distance reflects compression of the mol­ecule along its principal axis by intermolecular non‐bonded interactions.