Pub Date : 2023-11-22DOI: 10.1088/1674-1056/ad0ec4
Lin Jiang, Min Li, Bao-qin Fu, Jiechao Cui, Qing Hou
Widely used as structural materials in nuclear reactors, iron (Fe) -based alloys experience significant changes in their microstructure and macroscopic properties under high flux neutron irradiation during operation, posing issues associated with the safe operation of nuclear reactors. In this work, a molecular dynamics simulation approach incorporating electronic effects was developed for investigating the primary radiation damage process in α-Fe. Specifically, the influence of electronic effects on the collision cascade in Fe was systematically evaluated based on two commonly used interatomic potentials for Fe. The simulation results revealed that both electronic stopping (ES) and electron–phonon coupling (EPC) contribute to a reduction in the number of defects in the thermal spike phase. The application of ES decreases the number of residual defects after the cascade evolution, whereas EPC has a reverse effect. The introduction of electronic effects promotes the dispersive subcascade formation: ES significantly alters the geometry of the damaged region in the thermal spike phase, whereas EPC mainly reduces the extent of the damaged region. Furthermore, the incorporation of electronic effects effectively mitigates the discrepancies in simulation outcomes when using different interatomic potentials.
{"title":"Electronic effects on radiation damage in α-iron: a molecular dynamics study","authors":"Lin Jiang, Min Li, Bao-qin Fu, Jiechao Cui, Qing Hou","doi":"10.1088/1674-1056/ad0ec4","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0ec4","url":null,"abstract":"Widely used as structural materials in nuclear reactors, iron (Fe) -based alloys experience significant changes in their microstructure and macroscopic properties under high flux neutron irradiation during operation, posing issues associated with the safe operation of nuclear reactors. In this work, a molecular dynamics simulation approach incorporating electronic effects was developed for investigating the primary radiation damage process in α-Fe. Specifically, the influence of electronic effects on the collision cascade in Fe was systematically evaluated based on two commonly used interatomic potentials for Fe. The simulation results revealed that both electronic stopping (ES) and electron–phonon coupling (EPC) contribute to a reduction in the number of defects in the thermal spike phase. The application of ES decreases the number of residual defects after the cascade evolution, whereas EPC has a reverse effect. The introduction of electronic effects promotes the dispersive subcascade formation: ES significantly alters the geometry of the damaged region in the thermal spike phase, whereas EPC mainly reduces the extent of the damaged region. Furthermore, the incorporation of electronic effects effectively mitigates the discrepancies in simulation outcomes when using different interatomic potentials.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"69 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139248653","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}
Pub Date : 2023-11-22DOI: 10.1088/1674-1056/ad0ec7
Lei L L, He L J, Liao Q H, Liu W X, Yu T B
A phoxonic crystal waveguide with the glide symmetry is designed, in which both electromagnetic and elastic waves can propagate along the glide plane at the same time. Due to the glide symmetry, the bands of the phoxonic crystal super-cell degenerate in pairs at the boundary of the Brillouin zone. This is the so-called band-sticking effect and it causes the appearance of gapless guided-modes. By adjusting the magnitude of the glide dislocation the edge bandgaps, the bandgap of the guided-modes at the boundary of the Brillouin zone, can be further adjusted. The photonic and phononic guided-modes can then possess only one mode for a certain frequency with relatively low group velocities, achieving single-mode guided-bands with relatively flat dispersion relationship. In addition, there exists acousto-optic interaction in the cavity constructed by the glide plane. The proposed waveguide has potential applications in the design of novel optomechanical devices.
{"title":"Simultaneous guidance of electromagnetic and elastic waves via glide symmetry phoxonic crystal waveguides","authors":"Lei L L, He L J, Liao Q H, Liu W X, Yu T B","doi":"10.1088/1674-1056/ad0ec7","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0ec7","url":null,"abstract":"A phoxonic crystal waveguide with the glide symmetry is designed, in which both electromagnetic and elastic waves can propagate along the glide plane at the same time. Due to the glide symmetry, the bands of the phoxonic crystal super-cell degenerate in pairs at the boundary of the Brillouin zone. This is the so-called band-sticking effect and it causes the appearance of gapless guided-modes. By adjusting the magnitude of the glide dislocation the edge bandgaps, the bandgap of the guided-modes at the boundary of the Brillouin zone, can be further adjusted. The photonic and phononic guided-modes can then possess only one mode for a certain frequency with relatively low group velocities, achieving single-mode guided-bands with relatively flat dispersion relationship. In addition, there exists acousto-optic interaction in the cavity constructed by the glide plane. The proposed waveguide has potential applications in the design of novel optomechanical devices.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"27 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139250554","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}
Pub Date : 2023-11-22DOI: 10.1088/1674-1056/ad0ec6
Jiangtao Li, Qiannan Wang, Liang Xu, Lei Liu, Hang Zhang, S. Takagi, K. Ichiyanagi, Ryo Fukaya, Shunsuke Nozawa, Jianbo Hu
A time-resolved X-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth. Results reveal a retarded transformation from the shock-induced Bi-V phase to a metastable Bi-IV phase during the shock release, instead of the thermodynamically stable Bi-III phase. The emergence of the metastable Bi-IV phase is understood by the competitive interplay between two transformation pathways towards the Bi-IV and the Bi-III, respectively. The former is more rapid than the latter because the Bi-V to B-IV transformation is driven by the interaction between the closest atoms while the Bi-V to B-III transformation requires the interaction between the second closest atoms. The nucleation time for the Bi-V to Bi-IV transformation is determined to be 5.1± 0.9 ns according to a classical nucleation model. This observation demonstrates the importance of the formation of the transient metastable phases, which is able to change the phase transformation pathway in a dynamic process.
{"title":"In situ observation of the phase transformation kinetics of bismuth during shock release","authors":"Jiangtao Li, Qiannan Wang, Liang Xu, Lei Liu, Hang Zhang, S. Takagi, K. Ichiyanagi, Ryo Fukaya, Shunsuke Nozawa, Jianbo Hu","doi":"10.1088/1674-1056/ad0ec6","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0ec6","url":null,"abstract":"A time-resolved X-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth. Results reveal a retarded transformation from the shock-induced Bi-V phase to a metastable Bi-IV phase during the shock release, instead of the thermodynamically stable Bi-III phase. The emergence of the metastable Bi-IV phase is understood by the competitive interplay between two transformation pathways towards the Bi-IV and the Bi-III, respectively. The former is more rapid than the latter because the Bi-V to B-IV transformation is driven by the interaction between the closest atoms while the Bi-V to B-III transformation requires the interaction between the second closest atoms. The nucleation time for the Bi-V to Bi-IV transformation is determined to be 5.1± 0.9 ns according to a classical nucleation model. This observation demonstrates the importance of the formation of the transient metastable phases, which is able to change the phase transformation pathway in a dynamic process.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"6 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139248028","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}
Pub Date : 2023-11-21DOI: 10.1088/1674-1056/ad0e5b
Leliang Li, Guike Li, Zhao Zhang, Jian Liu, Nanjian Wu, Kai-You Wang, Nan Qi, Liyuan Liu
The performance of optical interconnection has improved dramatically in recent years. Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection, which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip, but also improves the system performance through advanced heterogeneous integrated packaging. This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection. The research status, development trend and application of ultra-low loss optical waveguides, high-speed detectors, high-speed modulators, lasers and 2D, 2.5D, 3D and monolithic integration are focused on.
{"title":"Silicon-based Optoelectronic Heterogeneous Integration for Optical Interconnection","authors":"Leliang Li, Guike Li, Zhao Zhang, Jian Liu, Nanjian Wu, Kai-You Wang, Nan Qi, Liyuan Liu","doi":"10.1088/1674-1056/ad0e5b","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0e5b","url":null,"abstract":"The performance of optical interconnection has improved dramatically in recent years. Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection, which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip, but also improves the system performance through advanced heterogeneous integrated packaging. This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection. The research status, development trend and application of ultra-low loss optical waveguides, high-speed detectors, high-speed modulators, lasers and 2D, 2.5D, 3D and monolithic integration are focused on.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139250934","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}
Pub Date : 2023-11-21DOI: 10.1088/1674-1056/ad0e5c
Yuhao Li, Xiaodong Fan, Z. Jia, Lu Fan, G. Ding, Xincai Liu, Shuai Guo, Bo Zheng, Shuai Cao, Ren-jie Chen, Aru Yan
The grain boundary phase affects the magnetic properties and corrosion resistance of sintered NdFeB magnets. In this work, a small amount of Indium (In) was added to the NdFeB magnet by induction melting to systematically investigate its effect on the evolution of the microstructure, magnetic properties, and corrosion resistance of the NdFeB magnet. The microstructural analysis illustrated that minor In-addition generated more grain boundary phases and an abundant amorphous phase at the triple junction grain boundary. While the addition of In element failed to enhance the magnetic isolation effect between adjacent matrix grains, fortuitously, its incorporation elevated the electrochemical potential of the In-containing magnets. Besides, during corrosion, an In-rich precipitate phase formed, hindering the ingress of the corrosive medium into the magnet. Consequently, this significantly bolstered the corrosion resistance of sintered NdFeB magnets. The phase formation, magnetic properties, and corrosion resistance of In-doped NdFeB magnets are detailed in this work, which provides a new prospect for the preparation of high-performance sintered NdFeB magnets.
晶界相会影响烧结钕铁硼磁体的磁性能和耐腐蚀性。在这项工作中，通过感应熔炼向钕铁硼磁体中添加了少量的铟（In），以系统地研究其对钕铁硼磁体的微观结构、磁性能和耐腐蚀性能演变的影响。微观结构分析表明，少量铟元素的添加会产生更多的晶界相，并在三交界晶界产生大量非晶相。虽然铟元素的加入未能增强相邻基体晶粒之间的磁隔离效果，但却幸运地提高了含铟磁体的电化学电位。此外，在腐蚀过程中，形成了富含 In 的沉淀相，阻碍了腐蚀介质进入磁体。因此，这大大增强了烧结钕铁硼磁体的耐腐蚀性。这项研究详细阐述了掺铟钕铁硼磁体的相形成、磁性能和耐腐蚀性，为制备高性能烧结钕铁硼磁体提供了新的前景。
{"title":"The effect of In-doping on the evolution of microstructure, magnetic properties, and corrosion resistance of NdFeB magnet","authors":"Yuhao Li, Xiaodong Fan, Z. Jia, Lu Fan, G. Ding, Xincai Liu, Shuai Guo, Bo Zheng, Shuai Cao, Ren-jie Chen, Aru Yan","doi":"10.1088/1674-1056/ad0e5c","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0e5c","url":null,"abstract":"The grain boundary phase affects the magnetic properties and corrosion resistance of sintered NdFeB magnets. In this work, a small amount of Indium (In) was added to the NdFeB magnet by induction melting to systematically investigate its effect on the evolution of the microstructure, magnetic properties, and corrosion resistance of the NdFeB magnet. The microstructural analysis illustrated that minor In-addition generated more grain boundary phases and an abundant amorphous phase at the triple junction grain boundary. While the addition of In element failed to enhance the magnetic isolation effect between adjacent matrix grains, fortuitously, its incorporation elevated the electrochemical potential of the In-containing magnets. Besides, during corrosion, an In-rich precipitate phase formed, hindering the ingress of the corrosive medium into the magnet. Consequently, this significantly bolstered the corrosion resistance of sintered NdFeB magnets. The phase formation, magnetic properties, and corrosion resistance of In-doped NdFeB magnets are detailed in this work, which provides a new prospect for the preparation of high-performance sintered NdFeB magnets.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"33 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253362","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}
High-resolution time- and angle-resolved photoemission measurements were conducted on the topological insulator ZrTe5. With strong femtosecond photoexcitation, a possible ultrafast phase transition from a weak to a strong topological insulating phase was experimentally realized by recovering the energy gap inversion in a time scale that was shorter than 0.15 ps. This photoinduced transient strong topological phase can last longer than 2 ps at the highest excitation fluence studied, and it cannot be attributed to the photoinduced heating of electrons or modification of the conduction band filling. Additionally, the measured unoccupied electronic states are consistent with the first-principles calculation based on experimental crystal lattice constants, which favor a strong topological insulating phase. These findings provide new insights into the longstanding controversy about the strong and weak topological properties in ZrTe5, and they suggest that many-body effects including electron–electron interactions must be taken into account to understand the equilibrium weak topological insulating phase in ZrTe5.
{"title":"Optical manipulation of the topological phase in ZrTe5 revealed by time- and angle-resolved photoemission","authors":"Chaozhi Huang, Chengyang Xu, F. Zhu, Shaofeng Duan, Jianzhe Liu, Lingxiao Gu, Shichong Wang, Haoran Liu, Dong Qian, Weidong Luo, Wentao Zhang","doi":"10.1088/1674-1056/ad0d9d","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0d9d","url":null,"abstract":"High-resolution time- and angle-resolved photoemission measurements were conducted on the topological insulator ZrTe5. With strong femtosecond photoexcitation, a possible ultrafast phase transition from a weak to a strong topological insulating phase was experimentally realized by recovering the energy gap inversion in a time scale that was shorter than 0.15 ps. This photoinduced transient strong topological phase can last longer than 2 ps at the highest excitation fluence studied, and it cannot be attributed to the photoinduced heating of electrons or modification of the conduction band filling. Additionally, the measured unoccupied electronic states are consistent with the first-principles calculation based on experimental crystal lattice constants, which favor a strong topological insulating phase. These findings provide new insights into the longstanding controversy about the strong and weak topological properties in ZrTe5, and they suggest that many-body effects including electron–electron interactions must be taken into account to understand the equilibrium weak topological insulating phase in ZrTe5.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"39 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139263685","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}
Pub Date : 2023-11-16DOI: 10.1088/1674-1056/ad0ccf
Huan Ma, Ning Tan, Xuchuan Wu, Man Li, Yiyan Wang, Hong-Yan Lu, Tianlong Xia, Shancai Wang
In this work, we investigate the electronic structure of NbGeSb with non-symmorphic symmetry. We employ angle-resolved photoemission spectroscopy to observe and identify the bulk and surface states over the Brillouin zone. By utilizing high-energy photons, we identify the bulk Fermi surface and bulk nodal line along the direction X-R, while the Fermi surface of the surface state is observed by using low-energy photons. We observe the splitting of surface bands away from the high-symmetry point $overline{mathrm{X}}$. The density functional theory calculations on bulk and 1 to 5-layer slab models, as well as spin textures of NbGeSb, verify that the band splitting could be attributed to the Rashba-like spin- orbit coupling caused by space-inversion-symmetry breaking at the surface. These splitted surface bands cross with each other, forming two-dimensional Weyl-like crossings that are protected by mirror symmetry. Our findings provide insights into the two-dimensional topological and symmetry- protected band inversion of surface states.
{"title":"Angle-resolved photoemission study of NbGeSb with non-symmorphic symmetry","authors":"Huan Ma, Ning Tan, Xuchuan Wu, Man Li, Yiyan Wang, Hong-Yan Lu, Tianlong Xia, Shancai Wang","doi":"10.1088/1674-1056/ad0ccf","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0ccf","url":null,"abstract":"In this work, we investigate the electronic structure of NbGeSb with non-symmorphic symmetry. We employ angle-resolved photoemission spectroscopy to observe and identify the bulk and surface states over the Brillouin zone. By utilizing high-energy photons, we identify the bulk Fermi surface and bulk nodal line along the direction X-R, while the Fermi surface of the surface state is observed by using low-energy photons. We observe the splitting of surface bands away from the high-symmetry point $overline{mathrm{X}}$. The density functional theory calculations on bulk and 1 to 5-layer slab models, as well as spin textures of NbGeSb, verify that the band splitting could be attributed to the Rashba-like spin- orbit coupling caused by space-inversion-symmetry breaking at the surface. These splitted surface bands cross with each other, forming two-dimensional Weyl-like crossings that are protected by mirror symmetry. Our findings provide insights into the two-dimensional topological and symmetry- protected band inversion of surface states.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"PC-24 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139268316","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}
Pub Date : 2023-11-16DOI: 10.1088/1674-1056/ad0cca
Xin Liu, Meng-Yu Tian, Xiaolan Cui, Xin-He Zhang
In a two-frequency cavity driving and atom driving atom-cavity system, we find the photon blockade effect. In a truncated eigenstates space, we calculate the zero-delay second-order correlation function of the cavity mode analytically and obtain an optimal condition for the photon blockade. By including three transition pathways, we find the higher excitations of the cavity mode can be further suppressed and the zero-delay second-order correlation function can be reduced additionally. Based on the master equation, we simulate the system evolution and find the analytical solutions match well with the numerical results. Our scheme is rubust with small fluctuations of parameters and maybe used as a new type of single photon source.
{"title":"Unconventional photon blockade in the two-photon Jaynes-Cummings model with two-frequency cavity drivings and atom driving","authors":"Xin Liu, Meng-Yu Tian, Xiaolan Cui, Xin-He Zhang","doi":"10.1088/1674-1056/ad0cca","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0cca","url":null,"abstract":"In a two-frequency cavity driving and atom driving atom-cavity system, we find the photon blockade effect. In a truncated eigenstates space, we calculate the zero-delay second-order correlation function of the cavity mode analytically and obtain an optimal condition for the photon blockade. By including three transition pathways, we find the higher excitations of the cavity mode can be further suppressed and the zero-delay second-order correlation function can be reduced additionally. Based on the master equation, we simulate the system evolution and find the analytical solutions match well with the numerical results. Our scheme is rubust with small fluctuations of parameters and maybe used as a new type of single photon source.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"51 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139268088","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}
Pub Date : 2023-11-16DOI: 10.1088/1674-1056/ad0cc7
Ting-Yu Liu, Zhao Wei, Wang Tao, Xiao-Dong An, Wei Lai, Yi-Neng Huang
Fractional molecular field theory (FMFT) is a phenomenological theory that describes phase transitions in crystals with randomly distributed components, such as the relaxor-ferroelectrics and spin glasses. In order to verify the feasibility of this theory, this paper fits it to the Monte Carlo simulations of specific heat and susceptibility vs temperature of two-dimensional random-site Ising model (2D-RSIM). The results indicate that FMFT deviates from 2D-RSIM significantly. The main reason for the deviation is that 2D-RSIM is a typical system of component random distribution, where the real order parameter is spatially heterogeneous and has no symmetry of space translation, but the basic assumption of FMFT means that the parameter is spatially uniform and has symmetry of space translation.
{"title":"Comparative Study on the Phase Transition Behaviors of Fractional Molecular Field Theory and Random-Site Ising Model","authors":"Ting-Yu Liu, Zhao Wei, Wang Tao, Xiao-Dong An, Wei Lai, Yi-Neng Huang","doi":"10.1088/1674-1056/ad0cc7","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0cc7","url":null,"abstract":"Fractional molecular field theory (FMFT) is a phenomenological theory that describes phase transitions in crystals with randomly distributed components, such as the relaxor-ferroelectrics and spin glasses. In order to verify the feasibility of this theory, this paper fits it to the Monte Carlo simulations of specific heat and susceptibility vs temperature of two-dimensional random-site Ising model (2D-RSIM). The results indicate that FMFT deviates from 2D-RSIM significantly. The main reason for the deviation is that 2D-RSIM is a typical system of component random distribution, where the real order parameter is spatially heterogeneous and has no symmetry of space translation, but the basic assumption of FMFT means that the parameter is spatially uniform and has symmetry of space translation.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"C-36 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139267262","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}
Pub Date : 2023-11-16DOI: 10.1088/1674-1056/ad0cc9
Kun Zhou, Han Wang
Fewest-switches surfacing hopping (FSSH) simulations have been performed with the highlevel multi-reference electronic structure method to explore the coupled electronic and nuclear dynamics upon photoexcitation of cyanogen bromide (BrCN). The potential energy surfaces (PES) of BrCN are charted as functions of the Jacobi coordinates (R, θ). An in-depth examination of the FSSH trajectories reveals the temporal dynamics of the molecule and the population changes of the lowest twelve states during BrCN's photodissociation process, which presents a rich tapestry of dynamical information. Furthermore, the carbon K-edge X-ray absorption spectroscopy (XAS) are calculated with multi-reference inner-shell spectral simulations. The rotation of the CN fragment and the elongation of the C-Br bond are found to be the reason of the peak shifting in the XAS. Our findings offer a nuanced interpretation for inner-shell probe investigations of BrCN, setting the stage for a deeper understanding of photodissociation process of cyanogen halides molecules
利用高水平多参考电子结构方法进行了最小开关表面跳变（FSSH）模拟，以探索溴化氰（BrCN）在光激发时的电子和核耦合动力学。溴化氰的势能面（PES）是雅可比坐标（R、θ）的函数。对 FSSH 轨迹的深入研究揭示了 BrCN 光解离过程中分子的时间动态和最低十二态的种群变化，呈现出丰富的动态信息。此外，还利用多参考内壳光谱模拟计算了碳 K 边 X 射线吸收光谱（XAS）。我们发现，CN 片段的旋转和 C-Br 键的伸长是 XAS 中峰值移动的原因。我们的发现为 BrCN 的内壳探针研究提供了细微的解释，为更深入地了解卤化氰分子的光解离过程奠定了基础。
{"title":"The study of the core-level spectroscopy of the photodissociation process of BrCN molecule","authors":"Kun Zhou, Han Wang","doi":"10.1088/1674-1056/ad0cc9","DOIUrl":"https://doi.org/10.1088/1674-1056/ad0cc9","url":null,"abstract":"Fewest-switches surfacing hopping (FSSH) simulations have been performed with the highlevel multi-reference electronic structure method to explore the coupled electronic and nuclear dynamics upon photoexcitation of cyanogen bromide (BrCN). The potential energy surfaces (PES) of BrCN are charted as functions of the Jacobi coordinates (R, θ). An in-depth examination of the FSSH trajectories reveals the temporal dynamics of the molecule and the population changes of the lowest twelve states during BrCN's photodissociation process, which presents a rich tapestry of dynamical information. Furthermore, the carbon K-edge X-ray absorption spectroscopy (XAS) are calculated with multi-reference inner-shell spectral simulations. The rotation of the CN fragment and the elongation of the C-Br bond are found to be the reason of the peak shifting in the XAS. Our findings offer a nuanced interpretation for inner-shell probe investigations of BrCN, setting the stage for a deeper understanding of photodissociation process of cyanogen halides molecules","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"50 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139270300","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}
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