Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physics
Hyperspectral Infrared Imaging Of Surface Phonon-Polaritons In Srtio3, D. J. Lahneman, M. M. Qazilbash
Hyperspectral Infrared Imaging Of Surface Phonon-Polaritons In Srtio3, D. J. Lahneman, M. M. Qazilbash
Arts & Sciences Articles
Polaritons have a demonstrated impact on nanophotonic applications in the midinfrared through visible spectral range. Surface phonon-polaritons (SPhPs) offer a way to bring the potential of polaritons to the longer infrared wavelengths. Strontium titanate (STO) is a perovskite polar dielectric with diverse technologically advantageous properties and it can support SPhPs in a uniquely broad spectral range of the far infrared. Despite these advantages, STO has mostly been overlooked as a nanophotonic material. In this work we investigate SPhP propagation in STO in the far-infrared through midinfrared spectral range using broadband, near-field nanospectroscopy. We developed a tabletop, laser sustained plasma light …
Measurement Of The Beam-Normal Single-Spin Asymmetry For Elastic Electron Scattering From ^12c And ^27al, D. Androic, David S. Armstrong, Et Al.
Measurement Of The Beam-Normal Single-Spin Asymmetry For Elastic Electron Scattering From ^12c And ^27al, D. Androic, David S. Armstrong, Et Al.
Arts & Sciences Articles
We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries Bn on 12C and 27Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of Bn on 12C and provide a first measurement on 27Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average laboratory scattering angle for both targets was 7.7∘, and the average Q2 for both targets was 0.024 37 GeV2 (Q=0.1561 GeV). The asymmetries are Bn=−10.68±0.90(stat)±0.57(syst) ppm for 12C and Bn=−12.16±0.58(stat)±0.62(syst) ppm …
Accurate Determination Of The Neutron Skin Thickness Of ^208pb Through Parity-Violation In Electron Scattering, D. Adhikari, (...), David S. Armstrong, Et Al.
Accurate Determination Of The Neutron Skin Thickness Of ^208pb Through Parity-Violation In Electron Scattering, D. Adhikari, (...), David S. Armstrong, Et Al.
Arts & Sciences Articles
We report a precision measurement of the parity-violating asymmetry APV in the elastic scattering of longitudinally polarized electrons from 208Pb. We measure APV=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor FW(Q2=0.00616 GeV2)=0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is Rn−Rp=0.283±0.071 fm. The result also yields the first significant direct measurement of the interior weak density of 208Pb: ρ0W=−0.0796±0.0036(exp)±0.0013(theo) fm−3 leading to the interior baryon density ρ0b=0.1480±0.0036(exp)±0.0013(theo) fm−3. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and …
Partially Metal-Coated Tips For Near-Field Nanospectroscopy, Yujia Zhang, Xinzhong Chen, (...), M. M. Qazilbash, Et Al.
Partially Metal-Coated Tips For Near-Field Nanospectroscopy, Yujia Zhang, Xinzhong Chen, (...), M. M. Qazilbash, Et Al.
Arts & Sciences Articles
Scanning probes with functional optical responses are key components of scanning near-field optical microscopes. For nanospectroscopy performed at IR and terahertz (THz) frequencies, one major challenge is that the commonly used metal-coated silicon tips yield nonadjustable coupling efficiency across the spectrum, which greatly limits the signal-to-noise ratio. Here, we test the possibility of a generic design scheme for wavelength-selective tip enhancement via finite-element numerical modeling. We employ a Si-based tip with various gold-coating lengths on the top, yielding a customizable near-field field strength at the tip apex. Calculations show a wavelength-dependent enhancement factor of the metal-coated tip due to the …