The optical absorption in ZnCdSe/ZnSe single quantum wells was studied by analyzing their reflectance spectra measured by a Fourier transform spectrometer. At lower temperatures, we observed a ...decrease in the excitonic absorption. This is qualitatively explained using a polariton model with the absorption dominated by phonon scattering. We present a comparison with III–V materials. The result confirms the polariton model of light propagation in quantum wells.
Optical properties of semiconductor quantum dots in magnetic fields are reviewed. A theory is described based on a multi-band effective-mass approximation with a nonparabolic conduction electron ...dispersion, the direct Coulomb interaction, and the electron-hole exchange interaction taken into account. The transition from the quantum-confined Zeeman effect for a weak magnetic field to the quantum-confined Paschen-Back effect to a strong magnetic field is discussed in comparison with atomic spectra in magnetic fields. Experimental results of the optical properties of isolated CuCl, CdSSe, and Si quantum dots in magnetic fields are also discussed in conjunction with the theoretical results.
The Astrophysical Journal, 848:141, 2017 We report an improved measurement of the cosmic microwave background (CMB)
$B$-mode polarization power spectrum with the POLARBEAR experiment at 150 GHz.
By ...adding new data collected during the second season of observations
(2013-2014) to re-analyzed data from the first season (2012-2013), we have
reduced twofold the band-power uncertainties. The band powers are reported over
angular multipoles $500 \leq \ell \leq 2100$, where the dominant $B$-mode
signal is expected to be due to the gravitational lensing of $E$-modes. We
reject the null hypothesis of no $B$-mode polarization at a confidence of
3.1$\sigma$ including both statistical and systematic uncertainties. We test
the consistency of the measured $B$-modes with the $\Lambda$ Cold Dark Matter
($\Lambda$CDM) framework by fitting for a single lensing amplitude parameter
$A_L$ relative to the Planck best-fit model prediction. We obtain $A_L = 0.60
^{+0.26} _{-0.24} ({\rm stat}) ^{+0.00} _{-0.04}({\rm inst}) \pm 0.14 ({\rm
foreground}) \pm 0.04 ({\rm multi})$, where $A_{L}=1$ is the fiducial
$\Lambda$CDM value, and the details of the reported uncertainties are explained
later in the manuscript.
