Condensed Matter Physics最新文献_第9页

Investigations on Cmc21-Si2P2X structures and physical properties by first-principles calculations 用第一性原理计算研究Cmc21-Si2P2X的结构和物理性质

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-12-18 DOI: 10.5488/CMP.24.43602

R. Yang, X. Gao, F. Wu, Q. Wei, M. Xue

{"title":"Investigations on Cmc21-Si2P2X structures and physical properties by first-principles calculations","authors":"R. Yang, X. Gao, F. Wu, Q. Wei, M. Xue","doi":"10.5488/CMP.24.43602","DOIUrl":"https://doi.org/10.5488/CMP.24.43602","url":null,"abstract":"The new structures, Cmc21-Si2P2X (X=S, Se, Te, and Po), are predicted, and their mechanical, electronic and optical properties are investigated with the density functional theory, by first principles calculations. The elastic constants of the four compounds are calculated by the stress-strain method. The calculations of the elastic stability criteria and phonon dispersion spectra imply that they are mechanically and dynamically stable at zero pressure. The mechanical parameters, such as shear moduli G, bulk moduli B, Young's moduli E and Poisson's ratios v are evaluated by the Voigt-Reuss-Hill approach. The Cmc21-Si2P2X has the largest hardness due to the largest Young's modulus in the four compounds, and it is a covalent crystal. The anisotropies of their mechanical properties are also analyzed. The band structures and densities of states, which are calculated by using HSE06, show that Cmc21-Si2P2X compounds are indirect bandgap semiconductors, and the values of the band gaps decrease with increasing atomic number from S, Se, Te, to Po. In addition, the longitudinal sound velocity and transverse sound velocity for Cmc21-Si2P2X have been investigated. The dielectric constant, electron energy loss, refractive index, reflectivity, absorption and conductivity are analyzed to gain the optical properties of Si2P2X.","PeriodicalId":10528,"journal":{"name":"Condensed Matter Physics","volume":"4 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91380319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Decoherence in open quantum systems: influence of the intrinsic bath dynamics 开放量子系统中的退相干:本征槽动力学的影响

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-12-10 DOI: 10.5488/CMP.25.13302

V. Ignatyuk, V. Morozov

引用次数: 1

Photo-switchable liquid crystalline brush as an aligning surface for liquid crystals: modelling via mesoscopic computer simulations 光开关液晶刷作为液晶的对准表面:通过介观计算机模拟建模

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-12-01 DOI: 10.5488/CMP.25.33601

D. Yaremchuk, T. Patsahan, J. Ilnytskyi

{"title":"Photo-switchable liquid crystalline brush as an aligning surface for liquid crystals: modelling via mesoscopic computer simulations","authors":"D. Yaremchuk, T. Patsahan, J. Ilnytskyi","doi":"10.5488/CMP.25.33601","DOIUrl":"https://doi.org/10.5488/CMP.25.33601","url":null,"abstract":"We consider the mesoscopic model for the liquid crystalline brush that might serve as a photoswitchable aligning surface for preorientation of low molecular weight liquid crystals in a bulk. The brush is built by grafting the polymer chains of a side-chain molecular architecture, with the side chains terminated by a chromophore unit mimicking the azobenzene unit, to a substrate. When irradiated with ultraviolet light, the chromophores photoisomerize into a non-mesogenic cis state and the whole system turns into an ordinary polymer brush with no orientational order and two states: the collapsed and straightened one, depending on the grafting density. When irradiated with visible light, the chromophores photoisomerize into a mesogenic trans state, resulting in formation of a transient network between chains because of a strong attraction between chromophores. Spontaneous self-assembly of the brush in these conditions results in an orientationally isotropic polydomain structure. The desired uniaxial planar ordering of chromophores within a brush can be achieved at certain temperature and grafting density intervals, as the result of a two-stage preparation protocol. An external stimulus orients chromophores uniaxially at the first stage. The system is equilibrated at the second stage at a given temperature and with the external stimulus switched off. The preoriented chromophores either keep or loose their orientations depending on the strength of the memory effect inherent to a transient network of chains that are formed during the first stage, similarly to the case of the liquid crystalline elastomers, where such effects are caused by the covalent crosslinks.","PeriodicalId":10528,"journal":{"name":"Condensed Matter Physics","volume":"1865 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72548112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Collective excitations in three-band superconductors 三波段超导体中的集体激发

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-11-24 DOI: 10.5488/CMP.26.23702

K. V. Grigorishin

引用次数: 0

A physicist's guide to the solution of Kummer's equation and confluent hypergeometric functions 物理学家对Kummer方程和合流超几何函数解的指导

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-11-08 DOI: 10.5488/CMP.25.33203

W. N. Mathews, M. A. Esrick, Z. Teoh, J. Freericks

{"title":"A physicist's guide to the solution of Kummer's equation and confluent hypergeometric functions","authors":"W. N. Mathews, M. A. Esrick, Z. Teoh, J. Freericks","doi":"10.5488/CMP.25.33203","DOIUrl":"https://doi.org/10.5488/CMP.25.33203","url":null,"abstract":"The confluent hypergeometric equation, also known as Kummer's equation, is one of the most important differential equations in physics, chemistry, and engineering. Its two power series solutions are the Kummer function, M(a,b,z), often referred to as the confluent hypergeometric function of the first kind, and M ≡ z1-bM(1+a-b, 2-b,z), where a and b are parameters that appear in the differential equation. A third function, the Tricomi function, U(a,b,z), sometimes referred to as the confluent hypergeometric function of the second kind, is also a solution of the confluent hypergeometric equation that is routinely used. Contrary to common procedure, all three of these functions (and more) must be considered in a search for the two linearly independent solutions of the confluent hypergeometric equation. There are situations, when a, b, and a - b are integers, where one of these functions is not defined, or two of the functions are not linearly independent, or one of the linearly independent solutions of the differential equation is different from these three functions. Many of these special cases correspond precisely to cases needed to solve problems in physics. This leads to significant confusion about how to work with confluent hypergeometric equations, in spite of authoritative references such as the NIST Digital Library of Mathematical Functions. Here, we carefully describe all of the different cases one has to consider and what the explicit formulas are for the two linearly independent solutions of the confluent hypergeometric equation. The procedure to properly solve the confluent hypergeometric equation is summarized in a convenient table. As an example, we use these solutions to study the bound states of the hydrogenic atom, correcting the standard treatment in textbooks. We also briefly consider the cutoff Coulomb potential. We hope that this guide will aid physicists to properly solve problems that involve the confluent hypergeometric differential equation.","PeriodicalId":10528,"journal":{"name":"Condensed Matter Physics","volume":"9 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74494149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Swelling of asymmetric pom-pom polymers in dilute solutions 不对称球团聚合物在稀溶液中的溶胀

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-11-02 DOI: 10.5488/CMP.25.23302

K. Haydukivska, O. Kalyuzhnyi, V. Blavatska, J. Ilnytskyi

{"title":"Swelling of asymmetric pom-pom polymers in dilute solutions","authors":"K. Haydukivska, O. Kalyuzhnyi, V. Blavatska, J. Ilnytskyi","doi":"10.5488/CMP.25.23302","DOIUrl":"https://doi.org/10.5488/CMP.25.23302","url":null,"abstract":"In this paper we continue our recent analysis [K. Haydukivska et al., J. Mol. Liq., 2021, 328, 115456] of complex molecules with two branching points at both ends of the linear backbone with f1 and f2 side arms starting from them, known as the pom-pom polymers. Here, we analyze the asymmetric case, f1 ≠ f2, by applying both the analytical approach, based on the direct polymer renormalization, and computer simulations using both dissipative particle dynamics and Monte Carlo methods. We study the role played by the molecular asymmetry of average polymer conformations, considering the infinite dilution regime and good solvent conditions.The quantitative estimates are reported for the set of universal size and shape characteristics of such molecules and for their individual branches, all the functions of f1 and f2. In particular, we evaluate the size ratio of the gyration radii of symmetric and asymmetric pom-pom topologies with the same molecular weight and quantitatively reveal an increase of the effective size of a molecule caused by its asymmetry. We also introduce and analyse the asymmetry factor and estimate the shift of the center of mass caused by the presence of side stars, which can serve as another characteristic of the asymmetry of pom-pom structure.","PeriodicalId":10528,"journal":{"name":"Condensed Matter Physics","volume":"40 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82062795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Thermodynamic perturbation theory and equation of state developments 热力学摄动理论和状态发展方程

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-10-09 DOI: 10.5488/CMP.24.33501

I. Nezbeda

引用次数: 0

Pressure dependence of solvation of non-polar solute in simple model of water 非极性溶质在简单水模型中溶化的压力依赖性

IF 0.6 4区物理与天体物理

Condensed Matter Physics Pub Date : 2021-10-09 DOI: 10.5488/CMP.24.33604

T. Urbič

引用次数: 0

Screening of ion-ion correlations in electrolyte solutions adsorbed in charged disordered matrices: Application of replica Ornstein-Zernike equations 在带电无序矩阵中吸附电解质溶液中离子-离子相关性的筛选:复制Ornstein-Zernike方程的应用