Article
Physics, Multidisciplinary
C. Robert, H. Dery, L. Ren, D. Van Tuan, E. Courtade, M. Yang, B. Urbaszek, D. Lagarde, K. Watanabe, T. Taniguchi, T. Amand, X. Marie
Summary: The study introduces a new method to access the respective contributions of conduction and valence bands to the Zeeman splitting in monolayer transition-metal dichalcogenides, providing valuable input parameters for band structure calculations of these 2D materials.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Tian-Xiang Liu, Mats-Erik Pistol, Craig Pryor, Li Mao
Summary: Tight binding models are commonly used in electronic structure calculations of nanostructures. In order to enhance computational efficiency, we propose a method that utilizes supercells, zone folding, and truncation of the Hamiltonians. Through experiments on a GaAs/AlAs quantum well, we find that this method significantly increases computational speed while only sacrificing a small measure of accuracy.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Mirjana Dimitrievska, Fredrik S. Hage, Simon Escobar Steinvall, Alexander P. Litvinchuk, Elias Z. Stutz, Quentin M. Ramasse, Anna Fontcuberta Morral
Summary: This study successfully characterizes the band structure of new compounds using high resolution electron energy-loss spectroscopy on nanowires, which correlates well with first principles calculations. This opens the way for non-destructive characterization of new materials and strengthens the route to new materials discovery.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Physics, Applied
Norio Akiyama, Tsukasa Dohi
Summary: The current-voltage characteristics of trigonal selenium nanowire crystals made via immersion in ethanol were studied, revealing a steep increase in current at the trap-filled limit voltage. Analysis based on a three-dimensional model estimated trap concentration and trap energy, compared with trap levels obtained from a photocurrent spectrum analysis. Different trap levels were attributed to deformation, OH- stretching mode, and CH- stretching mode.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Biochemical Research Methods
Imtiaz Ahmad, Suhail H. Serbaya, Ali Rizwan, Malik Sajjad Mehmood
Summary: The Small and Medium Development Authority of Pakistan focuses on introducing modern technologies and methods, as well as quality analysis for the gemstone industry. Through advanced spectroscopic techniques, the analysis of four natural gemstones from the Hunza valley revealed the presence of different elements and structural differences, providing important data for gemstone research.
JOURNAL OF SPECTROSCOPY
(2021)
Article
Materials Science, Multidisciplinary
R. Winkler, U. Zulicke
Summary: In this work, we use group theory to study electric, magnetic, and toroidal multipolar order in crystalline solids and identify five categories of polarized matter based on symmetry analysis. We also develop a general formalism of indicators for individual multipole densities. Our work provides a general framework for classifying and expanding current understanding of multipolar order in complex materials.
Article
Nanoscience & Nanotechnology
Joseph Sink, Craig Pryor
Summary: Suitable tight-binding models for wurtzite III-V (non-nitride) and group-V materials are currently lacking in literature. Existing models for cubic-zincblende semiconductors result in inaccurate band structures for hexagonal polytypes. Wurtzite parameters are useful for modeling nanowires condensing into either wurtzite or zincblende phases. We have developed spds tight-binding parameters for wurtzite crystal phase in non-nitride III-V and group V semiconductors, which, when combined with zincblende parameters, allow for modeling heterostructures with both crystal phases.
Article
Materials Science, Multidisciplinary
Krzysztof Gawarecki, Pawel Scharoch, Michal Wisniewski, Jakub Ziembicki, Herbert S. Maczko, Marta Gladysiewicz, Robert Kudrawiec
Summary: In this paper, a ready-to-use symmetry-invariant expansion of the full-zone 30-band k.p Hamiltonian for the Td point group is derived. The parameters are found by calculating the band structures of III-V materials using a state-of-the-art DFT approach and adjusting the k.p bands to match the targets. Satisfactory agreement between the k . p model and the DFT band structures is achieved for all tested zinc-blende III-V semiconductors. The fitted k . p parameters are also compared with values calculated using momentum matrix elements obtained directly from DFT.
Article
Nanoscience & Nanotechnology
Mouna Rafei, Vladimir Miranda La Hera, Hamid Reza-Barzegar, Eduardo Gracia-Espino, Thomas Wagberg
Summary: A detailed study was conducted on the oxidation of Cu substrates under controlled conditions. By adjusting the synthesis conditions, the formation of cuprous oxide (Cu2O) or cupric oxide (CuO) could be preferentially promoted. The oxidation temperature played a significant role in determining the formation of Cu2O or CuO, and controlling the temperature allowed tuning of the work function and ionization potential of the resulting film.