arXiv: Materials Science最新文献_第7页

Thermoelectric Power Factor Under Strain-Induced Band-Alignment in the Half-Heuslers NbCoSn and TiCoSb 半heuslers NbCoSn和TiCoSb中应变诱导带对准的热电功率因数

arXiv: Materials Science Pub Date : 2020-11-06 DOI: 10.1007/978-3-030-37790-8_10

C. Kumarasinghe, N. Neophytou

引用次数: 2

Terahertz radiation of jerk photocurrent 脉冲光电流的太赫兹辐射

arXiv: Materials Science Pub Date : 2020-11-06 DOI: 10.1103/physrevb.102.195410

B. Mendoza, Benjamin M. Fregoso

引用次数: 0

Split Ga vacancies and the unusually strong anisotropy of positron annihilation spectra in β−Ga2O3 β−Ga2O3中Ga空位的分裂和正电子湮灭谱的异常强的各向异性

arXiv: Materials Science Pub Date : 2020-11-04 DOI: 10.1103/physrevb.102.195207

A. Karjalainen, V. Prozheeva, K. Simula, I. Makkonen, V. Callewaert, J. Varley, F. Tuomisto

引用次数: 20

All-electron periodic G0W0 implementation with numerical atomic orbital basis functions: Algorithm and benchmarks 具有数值原子轨道基函数的全电子周期G0W0实现:算法和基准

arXiv: Materials Science Pub Date : 2020-11-03 DOI: 10.1103/PHYSREVMATERIALS.5.013807

X. Ren, F. Merz, Hong Jiang, Yi Yao, M. Rampp, H. Lederer, V. Blum, M. Scheffler

{"title":"All-electron periodic \u0000G0W0\u0000 implementation with numerical atomic orbital basis functions: Algorithm and benchmarks","authors":"X. Ren, F. Merz, Hong Jiang, Yi Yao, M. Rampp, H. Lederer, V. Blum, M. Scheffler","doi":"10.1103/PHYSREVMATERIALS.5.013807","DOIUrl":"https://doi.org/10.1103/PHYSREVMATERIALS.5.013807","url":null,"abstract":"We present an all-electron, periodic {GnWn} implementation within the numerical atomic orbital (NAO) basis framework. A localized variant of the resolution-of-the-identity (RI) approximation is employed to significantly reduce the computational cost of evaluating and storing the two-electron Coulomb repulsion integrals. We demonstrate that the error arising from localized RI approximation can be reduced to an insignificant level by enhancing the set of auxiliary basis functions, used to expand the products of two single-particle NAOs. An efficient algorithm is introduced to deal with the Coulomb singularity in the Brillouin zone sampling that is suitable for the NAO framework. We perform systematic convergence tests and identify a set of computational parameters, which can serve as the default choice for most practical purposes. Benchmark calculations are carried out for a set of prototypical semiconductors and insulators, and compared to independent reference values obtained from an independent $G_0W_0$ implementation based on linearized augmented plane waves (LAPW) plus high-energy localized orbitals (HLOs) basis set, as well as experimental results. With a moderate (FHI-aims textit{tier} 2) NAO basis set, our $G_0W_0$ calculations produce band gaps that typically lie in between the standard LAPW and the LAPW+HLO results. Complementing textit{tier} 2 with highly localized Slater-type orbitals (STOs), we find that the obtained band gaps show an overall convergence towards the LAPW+HLO results. The algorithms and techniques developed in this work pave the way for efficient implementations of correlated methods within the NAO framework.","PeriodicalId":8467,"journal":{"name":"arXiv: Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87435405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Simultaneous three-axis torque measurements of micromagnetism 微磁同步三轴转矩测量

arXiv: Materials Science Pub Date : 2020-11-03 DOI: 10.1063/9.0000106

K. R. Fast, J. Thibault, V. Sauer, M. Dunsmore, A. Kav, J. Losby, Z. Diao, E. Luber, M. Belov, M. R. Freeman

{"title":"Simultaneous three-axis torque measurements of micromagnetism","authors":"K. R. Fast, J. Thibault, V. Sauer, M. Dunsmore, A. Kav, J. Losby, Z. Diao, E. Luber, M. Belov, M. R. Freeman","doi":"10.1063/9.0000106","DOIUrl":"https://doi.org/10.1063/9.0000106","url":null,"abstract":"Measurements of magnetic torque are most commonly preformed about a single axis or component of torque. Such measurements are very useful for hysteresis measurements of thin film structures in particular, where high shape anisotropy yields a near-proportionality of in-plane magnetic moment and the magnetic torque along the perpendicular in-plane axis. A technique to measure the full magnetic torque vector (three orthogonal torque components) on micro- and nano-scale magnetic materials is introduced. The method is demonstrated using a modified, single-paddle silicon-on-insulator resonant torque sensor. The mechanical compliances to all three orthogonal torque components are maximized by clamping the sensor at a single point. Mechanically-resonant AC torques are driven by an RF field containing a frequency component for each fundamental torsional mode of the device, and the resulting displacements read out through optical position-sensitive detection. The measurements are compared with micromagnetic simulations of the mechanical torque to augment the interpretation of the signals. As an application example, simultaneous observations of hysteresis in the net magnetization along with the field-dependent in-plane anisotropy is highly beneficial for studies of exchange bias.","PeriodicalId":8467,"journal":{"name":"arXiv: Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79561588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Ultrafast Control of Material Optical Properties via the Infrared Resonant Raman Effect 红外共振拉曼效应对材料光学特性的超快控制

arXiv: Materials Science Pub Date : 2020-11-03 DOI: 10.1103/PhysRevX.11.021067

G. Khalsa, N. Benedek, J. Moses

{"title":"Ultrafast Control of Material Optical Properties via the Infrared Resonant Raman Effect","authors":"G. Khalsa, N. Benedek, J. Moses","doi":"10.1103/PhysRevX.11.021067","DOIUrl":"https://doi.org/10.1103/PhysRevX.11.021067","url":null,"abstract":"The Raman effect -- inelastic scattering of light by lattice vibrations (phonons) -- is one of the workhorses in optical physics and a ubiquitous tool for characterization of crystalline materials. In the typical experimental frequency range, the Raman effect is dominated by changes to electronic dipoles by Raman-active phonons, but when light is tuned into the mid- and far-infrared, the Raman effect is rich with potential physical pathways due to the presence of additional material dipoles through the lattice. Here we derive symmetry relations and complete expressions for the optical susceptibility including all electronic and lattice mediated pathways for the Raman effect using a perturbative approach. We show that in insulating materials, when light is tuned to resonantly excite infrared active phonons, the Raman effect may be dominated by direct changes to the lattice polarizability induced by Raman-active phonons, a mechanism distinct from the recently investigated ionic Raman scattering. Using first-principles techniques we show that, in an archetypal insulating perovskite SrTiO$_3$, this infrared-resonant Raman effect can induce optical symmetry breaking and giant shifts to the refractive index which are tailored by the incident light polarization and infrared active phonon excited. Additionally, the nonlinear polarization pathway responsible for the infrared-resonant Raman effect contributes to the quasistatic control of crystalline structure that has been the focus of recent nonlinear phononics studies.","PeriodicalId":8467,"journal":{"name":"arXiv: Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80764100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

An attempt to simulate laser-induced all-optical spin switching in a crystalline ferrimagnet 在晶体铁磁体中模拟激光诱导的全光自旋开关的尝试

arXiv: Materials Science Pub Date : 2020-11-03 DOI: 10.1063/9.0000003

G. P. Zhang, R. Meadows, A. Tamayo, Y. Bai, T. George

引用次数: 4

Bi2Se3 thin films heteroepitaxially grown on α−RuCl3 在α−RuCl3上异质外延生长Bi2Se3薄膜

arXiv: Materials Science Pub Date : 2020-10-30 DOI: 10.1103/physrevmaterials.4.113404

J. Park, J. Jo, J. Sears, Young-June Kim, Miyoung Kim, P. Kim, G. Yi

{"title":"Bi2Se3\u0000 thin films heteroepitaxially grown on \u0000α−RuCl3","authors":"J. Park, J. Jo, J. Sears, Young-June Kim, Miyoung Kim, P. Kim, G. Yi","doi":"10.1103/physrevmaterials.4.113404","DOIUrl":"https://doi.org/10.1103/physrevmaterials.4.113404","url":null,"abstract":"Combining various two-dimensional materials into novel van der Waals (vdW) heterostructures has been shown to lead to new emergent quantum systems. A novel heterostructure composed of a vdW topological insulator (TI) such as Bi$_{2}$Se$_{3}$ with a quantum spin liquid (QSL) such as $alpha$-RuCl$_{3}$ is of great interest for the potential for the chiral Dirac electrons in the TI surface states to interact strongly with the fractionalized fermionic spin excitations in the QSL. We report the heteroepitaxial growth of Bi$_{2}$Se$_{3}$ thin films on $alpha$-RuCl$_{3}$ as well as the characterization of their structural and electrical properties. Bi$_{2}$Se$_{3}$ thin films with an atomically smooth and uniform surface are grown by molecular beam epitaxy. The heterostructure exhibits a preferential epitaxial relationship corresponding to $(5 times 5)-$Bi$_{2}$Se$_{3}/(2sqrt{3} times 2sqrt{3})R30deg-alpha$-RuCl$_{3}$ commensurate supercells with a periodicity of 1.2 nm. The formation of the superlattice despite a lattice mismatch as large as 60% is attributed to the van der Waals heteroepitaxy. Magnetotransport measurements as a function of temperature show Bi$_{2}$Se$_{3}$ films grown on $alpha$-RuCl$_{3}$ are heavily $n$-doped, $n_{e}$ ~10$^{14}$ cm$^{-2}$, with mobility $mu$ ~450 cm$^{2}$ V$^{-1}$ s$^{-1}$ at low temperatures.","PeriodicalId":8467,"journal":{"name":"arXiv: Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80523112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Quasi-indirect measurement of electrocaloric temperature change in PbSc0.5Ta0.5O3 via comparison of adiabatic and isothermal electrical polarization data 通过绝热和等温电极化数据的比较准间接测量PbSc0.5Ta0.5O3的电热温度变化

arXiv: Materials Science Pub Date : 2020-10-29 DOI: 10.1063/5.0037809

S. Crossley, R. Whatmore, N. Mathur, X. Moya

引用次数: 6

Photoelectric absorption cross section of silicon near the bandgap from room temperature to sub-Kelvin temperature 从室温到亚开尔文温度，硅在禁带附近的光电吸收截面

arXiv: Materials Science Pub Date : 2020-10-29 DOI: 10.1063/5.0038392

Chris Stanford, M. J. Wilson, B. Cabrera, M. Diamond, N. Kurinsky, R. Moffatt, F. Ponce, B. Krosigk, B. Young

引用次数: 1