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1. Validating scattering-induced (sub)millimetre disc polarization through the spectral index, wavelength-dependent polarization pattern, and polarization spectrum: the case of HD 163296

   https://doi.org/10.1093/mnras/staa1499  

   Lin, Zhe-Yu Daniel ; Li, Zhi-Yun ; Yang, Haifeng ; Looney, Leslie ; Stephens, Ian ; Hull, Charles L ( July 2020 , Monthly Notices of the Royal Astronomical Society)

   ABSTRACT A number of young circumstellar discs show strikingly ordered (sub)millimetre polarization orientations along the minor axis, which is strong evidence for polarization due to scattering by ∼0.1 mm-sized grains. To test this mechanism further, we model the ALMA dust continuum and polarization data of HD 163296 using radmc-3d. We find that scattering by grains with a maximum size of 90  μm simultaneously reproduces the polarization observed at Band 7 and the unusually low spectral index (α ∼ 1.5) between Bands 7 and 6 in the optically thick inner disc as a result of more efficient scattering at the shorter wavelength. The low spectral index of ∼2.5 inferred for the optically thin gaps is reproduced by the same grains, as a result of telescope beam averaging of the gaps (with an intrinsic α ∼ 4) and their adjacent optically thick rings (where α ≲ 2). The tension between the grain sizes inferred from polarization and spectral index disappears because the low α values do not require large mm-sized grains. In addition, the polarization fraction has a unique azimuthal variation: higher along the major axis than the minor axis in the gaps, but vice versa in the rings. We find a rapidly declining polarization spectrum (with p ∝ λ−3 approximately) in the gaps, which becomes flattened or even inverted towards short wavelengths in the optically thick rings. These contrasting behaviours in the rings and gaps provide further tests for scattering-induced polarization via resolved multiwavelength observations. 

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2. Comment on “Chirality-Induced Electron Spin Polarization and Enantiospecific Response in Solid-State Cross-Polarization Nuclear Magnetic Resonance”

   https://doi.org/10.1021/acsnano.9b00221  

   Venkatesh, A. ; Wijesekara, Anuradha V. ; O'Dell, Luke A. ; Rossini, Aaron J. ( May 2019 , ACS nano)

   Recently, Santos et al. published an article titled “Chirality-Induced Electron Spin Polarization and Enantiospecific Response in Solid-State Cross-Polarization Nuclear Magnetic Resonance” in ACS Nano. In this article it was claimed that crystalline amino acid enantiomers can give rise to 1H-15N and 1H-13C cross-polarization magic angle spinning (CPMAS) solid-state NMR spectra with different relative signal intensities. The authors attributed such differences to transient changes in T1 relaxation times resulting from an interaction between the electron spins and the radiofrequency contact pulses used in the CPMAS experiment, and discussed this proposed phenomenon in terms of the chirality-induced spin selectivity (CISS) effect. We disagree with the authors conclusion that the CISS effect plays a role in the different signal intensities observed in the CPMAS solid-state NMR spectra of crystalline enantiomers. Quantitative 13C CPMAS experiments on aspartic acid enantiomers demonstrate that CPMAS signal variations can likely be attributed to sample dependent differences in T1 relaxation times rather than any chirality effects. 

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3. Implications of Pro- and Counterattitudinal Information Exposure for Affective Polarization: Partisan Media Exposure and Affective Polarization

   https://doi.org/10.1111/hcre.12028  

   Kelly Garrett, R. ; Gvirsman, Shira Dvir ; Johnson, Benjamin K. ; Tsfati, Yariv ; Neo, Rachel ; Dal, Aysenur ( July 2014 , Human Communication Research)
4. Silicon nitride polarization beam splitter based on polarization-independent MMIs and apodized Bragg gratings

   https://doi.org/10.1364/OE.420499  

   Zhan, Jiahao ; Brock, Joseph ; Veilleux, Sylvain ; Dagenais, Mario ( January 2021 , Optics Express)

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5. Analysis of signal-to-noise ratio of angle of polarization and degree of polarization

   https://doi.org/10.1364/OSAC.422541  

   Chen, Yingkai ; Zhu, Zhongmin ; Liang, Zuodong ; Iannucci, Leanne E. ; Lake, Spencer P. ; Gruev, Viktor ( April 2021 , OSA Continuum)