arXiv: Computational Physics最新文献_第4页

Strain tunable pudding-mold-type band structure and thermoelectric properties of SnP3 monolayer 应变可调布丁型SnP3单层带结构及热电性能

arXiv: Computational Physics Pub Date : 2019-12-27 DOI: 10.1063/5.0003241

Shasha Wei, Cong Wang, S. Fan, G. Gao

{"title":"Strain tunable pudding-mold-type band structure and thermoelectric properties of SnP3 monolayer","authors":"Shasha Wei, Cong Wang, S. Fan, G. Gao","doi":"10.1063/5.0003241","DOIUrl":"https://doi.org/10.1063/5.0003241","url":null,"abstract":"Recent studies indicated the interesting metal-to-semiconductor transition when layered bulk GeP3 and SnP3 are restricted to the monolayer or bilayer, and SnP3 monolayer has been predicted to possess high carrier mobility and promising thermoelectric performance. Here, we investigate the biaxial strain effect on the electronic and thermoelectric properties of SnP3 monolayer. Our first-principles calculations combined with Boltzmann transport theory indicate that SnP3 monolayer has the pudding-mold-type valence band structure, giving rise to a large p-type Seebeck coefficient and a high p-type power factor. The compressive biaxial strain can decrease the energy gap and result in the metallicity. In contrast, the tensile biaxial strain increases the energy gap, and increases the n-type Seebeck coefficient and decreases the n-type electrical conductivity. Although the lattice thermal conductivity becomes larger at a tensile biaxial strain due to the increased maximum frequency of the acoustic phonon modes and the increased phonon group velocity, it is still low, only e.g. 3.1 W/(mK) at room temperature with the 6% tensile biaxial strain. Therefore, SnP3 monolayer is a good thermoelectric material with low lattice thermal conductivity even at the 6% tensile strain, and the tensile strain is beneficial to the increase of the n-type Seebeck coefficient.","PeriodicalId":8424,"journal":{"name":"arXiv: Computational Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91440220","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: 13

NeuDATool: An open source neutron data analysis tools, supporting GPU hardware acceleration, and across-computer cluster nodes parallel NeuDATool:一个开源的中子数据分析工具，支持GPU硬件加速，以及跨计算机集群节点并行

arXiv: Computational Physics Pub Date : 2019-12-17 DOI: 10.1063/1674-0068/CJCP2005077

Changli Ma, He Cheng, Taisen Zuo, Guisheng Jiao, Zehua Han

{"title":"NeuDATool: An open source neutron data analysis tools, supporting GPU hardware acceleration, and across-computer cluster nodes parallel","authors":"Changli Ma, He Cheng, Taisen Zuo, Guisheng Jiao, Zehua Han","doi":"10.1063/1674-0068/CJCP2005077","DOIUrl":"https://doi.org/10.1063/1674-0068/CJCP2005077","url":null,"abstract":"Empirical potential structure refinement (EPSR) is a neutron scattering data analysis algorithm and a software package. It was developed by the British spallation neutron source (ISIS) Disordered Materials Group in 1980s, and aims to construct the most-probable atomic structures of disordered liquids. It has been extensively used during the past decades, and has generated reliable results. However, it is programmed in Fortran and implements a shared-memory architecture with OpenMP. With the extensive construction of supercomputer clusters and the widespread use of graphics processing unit (GPU) acceleration technology, it is now necessary to rebuild the EPSR with these techniques in the effort to improve its calculation speed. In this study, an open source framework NeuDATool is proposed. It is programmed in the object-oriented language C++, can be paralleled across nodes within a computer cluster, and supports GPU acceleration. The performance of NeuDATool has been tested with water and amorphous silica neutron scattering data. The test shows that the software could reconstruct the correct microstructure of the samples, and the calculation speed with GPU acceleration could increase by more than 400 times compared with CPU serial algorithm at a simulation box consists about 100 thousand atoms. NeuDATool provides another choice for scientists who are familiar with C++ programming and want to define specific models and algorithms for their analyses.","PeriodicalId":8424,"journal":{"name":"arXiv: Computational Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86700909","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

Rigidly rotating gravitationally bound systems of point particles, compared to polytropes 与多相体相比，点粒子的刚性旋转引力束缚系统

arXiv: Computational Physics Pub Date : 2019-11-04 DOI: 10.1142/S0129183120500904

Yngve Hopstad, J. Myrheim

{"title":"Rigidly rotating gravitationally bound systems of point particles, compared to polytropes","authors":"Yngve Hopstad, J. Myrheim","doi":"10.1142/S0129183120500904","DOIUrl":"https://doi.org/10.1142/S0129183120500904","url":null,"abstract":"In order to simulate rigidly rotating polytropes we have simulated systems of $N$ point particles, with $N$ up to 1800. Two particles at a distance $r$ interact by an attractive potential $-1/r$ and a repulsive potential $1/r^2$. The repulsion simulates the pressure in a polytropic gas of polytropic index $3/2$. We take the total angular momentum $L$ to be conserved, but not the total energy $E$. The particles are stationary in the rotating coordinate system. The rotational energy is $L^2/(2I)$ where $I$ is the moment of inertia. Configurations where the energy $E$ has a local minimum are stable. In the continuum limit $Ntoinfty$ the particles become more and more tightly packed in a finite volume, with the interparticle distances decreasing as $N^{-1/3}$. We argue that $N^{-1/3}$ is a good parameter for describing the continuum limit. We argue further that the continuum limit is the polytropic gas of index $3/2$. For example, the density profile of the nonrotating gas approaches that computed from the Lane--Emden equation describing the nonrotating polytropic gas. In the case of maximum rotation the instability occurs by the loss of particles from the equator, which becomes a sharp edge, as predicted by Jeans in his study of rotating polytropes. We describe the minimum energy nonrotating configurations for a number of small values of $N$.","PeriodicalId":8424,"journal":{"name":"arXiv: Computational Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88278370","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: 0

Dissipative modes, Purcell factors, and directional beta factors in gold bowtie nanoantenna structures 金领结纳米天线结构中的耗散模式、Purcell因子和定向β因子

arXiv: Computational Physics Pub Date : 2019-10-22 DOI: 10.1103/physrevb.102.155301

Chelsea Carlson, S. Hughes

引用次数: 8

A relativistic particle pusher for ultra-strong electromagnetic fields 一个用于超强电磁场的相对论粒子推进器

arXiv: Computational Physics Pub Date : 2019-10-10 DOI: 10.1017/S0022377820000719

Jérôme Pétri

{"title":"A relativistic particle pusher for ultra-strong electromagnetic fields","authors":"Jérôme Pétri","doi":"10.1017/S0022377820000719","DOIUrl":"https://doi.org/10.1017/S0022377820000719","url":null,"abstract":"Abridged. Kinetic plasma simulations are nowadays commonly used to study a wealth of non-linear behaviours and properties in laboratory and space plasmas. In particular, in high-energy physics and astrophysics, the plasma usually evolves in ultra-strong electromagnetic fields produced by intense laser beams for the former or by rotating compact objects such as neutron stars and black holes for the latter. In these ultra-strong electromagnetic fields, the gyro-period is several orders of magnitude smaller than the timescale on which we desire to investigate the plasma evolution. Some approximations are required like for instance artificially decreasing the electromagnetic field strength which is certainly not satisfactory. The main flaw of this downscaling is that it cannot reproduce particle acceleration to ultra-relativistic speeds with Lorentz factor above $gamma approx 10^3-10^4$. In this paper, we design a new algorithm able to catch particle motion and acceleration to Lorentz factor up to $10^{15}$ or even higher by using Lorentz boosts to special frames where the electric and magnetic field are parallel. Assuming that these fields are locally uniform in space and constant in time, we solve analytically the equation of motion in a tiny region smaller than the length scale of the spatial and temporal gradient of the field.","PeriodicalId":8424,"journal":{"name":"arXiv: Computational Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88760791","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: 8

Bond relaxation and electronic properties of two-dimensional Sb/MoSe2 and Sb/MoTe2 van der Waals heterostructures 二维Sb/MoSe2和Sb/MoTe2范德华异质结构的键弛豫和电子性质

arXiv: Computational Physics Pub Date : 2019-10-04 DOI: 10.1063/1.5130533

Maolin Bo, Hanze Li, Zhongkai Huang, Lei Li, Chuang Yao

引用次数: 4

Warm dense matter simulation via electron temperature dependent deep potential molecular dynamics 通过依赖于电子温度的深势分子动力学模拟热致密物质

arXiv: Computational Physics Pub Date : 2019-08-31 DOI: 10.1063/5.0023265

Yuzhi Zhang, Chang Gao, Qianrui Liu, Linfeng Zhang, Han Wang, Mohan Chen

引用次数: 20

A full Stokes subgrid model for simulation of grounding line migration in ice sheets using Elmer/ICE(v8.3) 使用Elmer/ ice (v8.3)模拟冰盖接地线迁移的全Stokes子网格模型

arXiv: Computational Physics Pub Date : 2019-08-28 DOI: 10.5194/gmd-2019-244

Gong Cheng, Per Lötstedt, L. von Sydow